For anyone interested in optimizing their Windows-based (HT)PC music source I wholeheartedly recommend downloading the free(!) "Fidelizer" program via below link(download option at the bottom of the page):

In short Fidelizer optimizes/economizes the environment on your (HT)PC, which can be done in three stages by shutting down processes not important to anything other than (roughly) the most basic needs with regard to A/V playback. As it says on their homepage:

Fidelizer has 3 optimization levels. They're all for the same goal to sonic improvements. I'll leave them all to your judge whether they're subtle or big difference. At any rate, you should leave your ears with it for at least week if it doesn't hurt your computer. Some people need time to adapt to changes.

The first ones is 'Professional'. This will optimize system to the extend that it won't significantly affect overall system performance. You can work as usual while enjoying improved multimedia experiences.

The next ones is 'Audiophile'. This is quite dedicated ones for those who pursue higher fidelity. It will lower system/network performance so audio can gain more priority to access to resources at time. It will also lower most processes including system ones to lowest level so you need to close your audiophile player before using it.

The last ones is 'Extremist'. As the name say, this isn't risk-free feature to try. It will stop most bundled system services leaving only important ones for audio. Yes, it will stop network services and such too. You may not know but Windows Audio and DHCP share the same process in service host provider so disabling network can significantly improve sonic performance. I also add some options to keep network and user experiences (HID,Tablet,Themes) working for some applications.

For general use, you should stick with 'Professional' level but computer in today's market should be able to use 'Audiophile' without hassle about system/network performance. I use 'Audiophile' level on AMD Phenom X2 550 BE machine and ended up running fine for 24/7 usage.....ya it's old and cheap unlike i7 or Athlon II X6 but it still works.

I'm using the 'Audiophile' level myself, and have experienced no problems at all nor any noticable limitations in the use of my HTPC. One of the people who was lead to Fidelizer via my initial recommendation(I stumbled upon Fidelizer from a recommmendation over at the JRiver forum) is a software programmer himself, and he's successfully tested Fidelizer quite thoroughly to see whether any glitches should occur that might be detrimental to the overall funcionality of the PC. As it's stated on the homepage any "newer"(even over 5 years, I suppose) computer shouldn't experience problems with the use of Fidelizer.

Taking up only 272kb Fidelizer has provided a noticable sound quality improvement not only in my setup, but also in all the setups of the audio-friends of mine to whom I've recommended the download. One of them even goes to say he's hardly heard a more substantial sonic upgrade in a long while(to which I definately agree), and with this in mind think about the following: Fidelizer is FREE!

Indeed I'm perplexed that this little wonder of a free program hasn't received more attention among the computer audiophiles, at least what I know of, and I certainly don't see any reason going about hiding its presence.

So, without much further ado: go ahead and download Fidelizer ASAP. Any questions, be they with regard to download/use or anything else, are welcomed.
I wholeheartedly agree. It's one badass upgrade - bigger improvement than some $$$ improvements I have made. If it doesn't work for you its very simple to delete, anyway.
waste of time. Jplay blows fidelizer out of the water, assuming that you play lossless vs midfi quality audio files
Davide256 --

All lossless WAV files played here, and via my quite
transparent setup Fidelizer is certainly not a waste of
time; it makes a very worthwhile difference with JRiver
MC18, and that for free. I'll just go ahead and say it
again: Fidelizer makes a VERY worthwhile difference, not
only in my setup.

Your "JPLAY blows Fidelizer out of the water"-
remark is, strictly speaking, somewhat besides the point;
Fidelizer is no playback software but a Windows-based (HT)PC
optimization tool, and as such makes comparisons to a
playback software moot. If you'd want to compare investments
- one free, the other not - into making better sound, I'd
say Fidelizer with an existing playback software like JRiver
MC18 holds as much potential as JPLAY sans Fidelizer, unless
perhaps where JPLAY's hibernation mode comes into play.
Indeed, being that Fidelizer is free and does what it does,
why not use it in conjunction with JPLAY as well?

No bashing on JPLAY, I must add. In terms of pure 2-channel
sound quality I find it's possibly the very best out
there, certainly in hibernation mode, but JRiver MC18
+ Fidelizer is very close. There's also cPLay, which is
free, and to my ears sounds very much like JPLAY. What I
like about the sonic "imprinting"(or lack hereof)
of cPlay and especially JPLAY is the natural, full-bodied,
and organic sound, where JRiver MC18 sans Fidelizer is
perhaps a wee bit more meager or even sterile, if you will.
However, Fidelizer seems to almost completely eradicate this
slight sterility via JRiver and brings with it a needed
organic element to the sound.
I couldn't get it to download.
Phusis, is this using MC18 over USB or Ethernet?
Phusis, you don't post your system but I see from one of your threads that you use the NuForce DAC-9... this has USB but its not listed as asynchronous. Without asynch usb computer audio is a lame duck. I run a PS Audio DLinkIII with the JKMkIII asynch USB converter. My PC server is optimized per computer audiophile service specs with the exception that network services are enabled

Running a quick A/B comparison of Fidelizer in extremist mode vs Jplay in Xtreme mode

RR -120 CD lead track,Brittens Orchestra
both harmonically correct. Fidelizer soggy on bass attack. Jplay deeper in bass with good attack. Fidelizer flat lifeless stereo image. Jplay presents good bloom for brass instruments spatial location

Paper Airplane by Alison Krauss and Union Station - lead track
both harmonically correct. Fidelizer flat and uninteresting. Jplay captures picked string leading transients and the richness of the acoustic guitar.

I will knock Jplay because it takes 6 seconds to respond to a mouse click once music starts playing in extreme mode, but I can live with that to get Porsche vs familiy sedan performance.
Davide256 --

I'm using the NuForce DAC-9, yes - the one that doesn't sport the asynchronous USB input that has since become standard with the DAC-9. However, it doesn't automatically follow that the USB input is the only way to go, although I did that to begin with; the preferable solution over isynchronous USB in my case has been to output from a professional RME 9632 soundcard via its XLR AES/EBU digital out to the DAC-9. The standard RME break-out cable has been replaced by a dedicated DIY digital cable with Mundorf silver/gold wires and Switchcraft connectors. This way of outputting to my ears clearly bests the isynchronous USB hook-up, and by all accounts the asynchronous variation isn't going to better my current connection. Instead the next digital interface update will be to invest in the Audiophilleo2 USB to S/PDIF converter + PurePower with direct BNC-BNC connection to my DAC-9. This will blow a stand-alone USB asynchronous connection even further out of the water, to use your way of going about it.

With regard to your impressions on JPLAY vs Fidelizer(+ a software?), what's the software used in conjunction with Fidelizer? I can't really make any further comments until getting that clear, and even so your comments, honest they may be, are put forth in a way that makes any worthwhile assessments on them very difficult.

Look, I have made my own conclusions on JPLAY's sonic attributes, and they simply don't mirror yours - at least not to the same degree. My own setup is quite capable, so it's not a matter of having shitty equipment badly implemented that can't reveal any differences to a notable extent. Like I said, I hold JPLAY in high esteem, but JRiver MC18 + Fidelizer in Audiophile mode comes extremely close.

Tonyptony --

As noted above.
Warning ****It appears to be a scam, trying to collect fees to access.
Ozzy --

Via the link my first post refers to, go to the bottom of the page just below the 'Fidelizer 2.1' window illustration and click 'Download Fidelizer' - that's it. No scam, no collecting fees or whatever.
phusis, i use JRiver MC 17, haven't shelled out yet for the 18 upgrade.
Phusis, It still sells I have to pay $29.95 for winzip to continue.
Ozzy --

Did you download via the link('Download Fidelizer') at the bottom of the homepage referred to above to begin with? As is I'd recommend you uninstall all Fidelizer related files you've downloaded already(i.e.: what you've downloaded that you would imagine is Fidelizer-related..), and start all over via referred 'Download Fidelizer' link.

Fidelizer is a free software for sure, so I'm a bit puzzled how you've ended being required to pay for a winzip file.
Nope, everything suggested just gets me to more add ons to my computer and no Fidelizer.
truly remarkable!....had grown use to hearing a microskip every once in a while (approx once every hour or so). not enough to drive me crazy but often enough to wish it would stop. have not heard a microskip since installing fidelizer two days ago (6 hours of listening). things sound slightly "better" too but am yet to do true a-b testing. off the cuff....i'm thinking better definition down low and smoother high's and mids. still wondering how and why but really enjoying it.

for the price (free!)...i am floored!. no reason not to try this one folks. it could make you feel silly about many pc audio tweaks you've tried in the past (that cost money and accomplished near nothing or less).

thank you again Phusis!
I installed it, but it does not show up in All Programs and there is no desktop icon for it. How do people run it after re-booting?
i created a shortcut on my desktop. click it and the install/settings window opens up. takes 5-10 seconds to install on my i5-3.4 pc
Levy03 - I can certainly do that. I was just surprised that once installed there does not seem to be any convenient way to run it. Installations, even for free software, normally create a shortcut for you. Just wanted to be sure I was not missing something.
Dtc...from what i understand, Fidelizer uninstalls itself at every boot. the program must be reloaded/reinstalled every time you restart. once installed and run, i don't think you can "turn it off"?. reboot required to do that which again, is an uninstall. no "convenient way to run it" because it can't be run/shut down period. only installed and removed at reboot.

a temporary program of sorts?? who knows?. have only been using it for a few days so hopefully someone with more knowledge about the program/topic will chime in (i set a low bar when it comes to computer know how). can tell you it's working very well for me.

I did not hear any advantage in running it, so I probably will uninstall it. It does not show up in the list to uninstall. I can delete the files, I am just not sure if it has done anything else. I guess I may need to go back to a restore point to do that. It might be a good program, but it is certainly unconventional in the way it installs.
Has anyone had a problem with Fidelizer fully starting up? I downloaded fine, run the application, can choose the settings (Extreme, Audiophile ), and then I even see some of the status screens while it is checking my Windows 7 settings. However, then nothing? I presume I should see some kind of player open up to actually play my music library? Am I missing something – any advice would be appreciated – have found almost nothing on the web.
Sbleam --

No worries, Fidelizer is doing what it's supposed to do just fine reading through your message above. After you've chosen your setting and pressed 'Fidelize' it then "does its thing" as indicated by the small process-window(status-screen), and when it's done the small window closes and a browser to their website pops up. Simply close the browser, and then start up your playback software. From here om Fidelizer has managed you PC according to your setting and closed down processes corresponding one of the three chosen stages - either Professional, Audiophile, or Extremist. I'd recommend you use the Audiophile setting, as it still allowes basic usage of your PC while having shut down a variety of processes that interferes with audio quality.

To achieve the desired effect of Fidelizer it is important that you run the program BEFORE you start up your playback software. Simply run Fidelizer as the first thing when you start up your PC, and Fidelizer will then continue its effect until reboot. That's also saying that you need to start up Fidelizer manually after every reboot, a small measure of action that only takes a few seconds.

Remember, Fidelizer only shuts down a variety of processes on your PC, and that's it. It's not a playback software to manage your music library; it simply "re-calibrates" your computer by shutting down processes that would otherwise interfere with audio quality in making the soft- hardware environment less "noisy." Fidelizer is simply "incognito" while running, the only visible effect of which is when you access the Task Manager under 'Services' and sees how many of them are stopped when scrolling down(compared to when Fidelizer is not in use).
Phusis - the problem I have with Fidelizer is that it does not act like a good Windows citizen. It does not register itself as a app, so you cannot delete it easily. It also does not provide an easy way to start it up on re-boot. Once runnng, it does not provide any way to know what it is doing. I wounder how many people think it is working after a reboot, when, the best I can tell, you actually have to restart it manually after each reboot. It may do what it is suppose to do, but for the casual user, it is very mysterious. Quite frankly, for the paranoid, it looks like a pretty suspicious program. I believe they need to work on making it user friendly if they really want people to use it.
Dtc --

For what it's worth a friend to a friend of mine, who is an avid audiophile himself, is a software programmer(as mentioned in my OP on this subject), and he's thoroughly tested Fidelizer to have a look at its "inner workings." From what I've been told nothing suspicious came of his conclusions that would warrant an alarming position with regard to the safety of using Fidelizer, and from all the posts I've read on people using Fidelizer none of them have expressed problems as in actually being confronted with problems from its use.

With regard to the (lack of) ease of starting up Fidelizer upon every reboot - and yes, you have to manually start Fidelizer after every reboot, and if you don't check Task Master und 'Processes' to confirm that it actually doesn't run - I don't see the problem. I've placed the Fidelizer icon in the task bar at the bottom of my Windows page next to JRiver and other icons, and from here on it's only a matter of seconds for Fidelizer to be up and running. Had there been an option for it to default start with every reboot, fine, I'd have greeted the opportunity. You should in fact be able to have Fidelizer start up automatically via the Windows settings, but you'd still have to go through the setting, press 'Fidelize,' and close the browser. As is I'm fine with it as is; it's a free program, the audible difference is significant, and what small setup there is is done within a matter of seconds.

Perhaps part of the answer to your wondering what it is Fidelizer is doing lies in its, for the casual user, intricate function in shutting down Windows services, but also because doing what it does is not playback related as such, and therefore has no inherently visible "user interface" you'd want or even need to go by. For more detailed information I'd simply access the Task Manager under 'Services,' where you can see the services running or stopped. For a reference you might want to access this information both with and without Fidelizer running.

I'd wager to disagree with your stance on the casual user seeing Fidelizer as a "mysterious" program. Granted, apart from being a casual user I may as well be somewhat naïve (or simply ignorant) into the workings of Windows programs, but I've had the fortunate pleasure of having beforementioned software programmer giving the Fidelizer program his "Approved" stamp, as far as he could tell, and from here on I've simply applied a pragmatic approach with the use of Fidelizer where, if no problems arose, I'll remain happy.
Don't get me wrong. I do not think Fidelizer is any threat to my system. But, to me, since it does not register itself so it can be deleted and because it does not have a startup option or a shutdown option, it appears more like a virus/trojan than a legitimate program. Personally I think that is a problem. Many casual users would have a hard time finding the executable and creating a shortcut to it. I cannot name another app on my system that requires that, even free ones. Also, the only way to return to normal operation of the system is to reboot. Just saying - I think they could work on their user friendliness.
Version 3.0 is released.
Fidelizer installed , admittedly improvement in sound but one thing that I loose control with JRemote in "Audiophile" mode is most inconvenient , hope network not affected if possible in the first 2 modes
How does one know Fidelizer is running, or is that the point of Dtc's comment - it doesn't show?

When I disabled JPlay (trial) and installed Fidelizer and rebooted, Win 8 Action Center shows a problem with Cygwin. Which of these two is that attached to?
Fidelizer doesn't 'run' anymore than your auto mechanic 'runs'. What it does is shut off or lower system priority for processes that aren't needed for audio. It hot rods your system temporarily for audio then puts it back where it started when you reboot. I always see the security icons complaining during this phase as Fidelizer retunes. I generally use Fidelizer in extremist mode as disabling network makes a significant improvement...the other stages don't make that much of a difference with Jplay 5.1 in Xstream mode
The simple answer to my question (Davide256), something I hadn't noticed, is that the user has to start fidelizer manually each time, and reboot to get rid of it.

Now, being aware of that, there are a bunch of problems:

1) fidelizer kills foobar2000's volume control (Windows Sound Mixer is not an efficient way to conrol volume on the fly, to say the least);

2) How can one A-B or A-B-C (with JPlay or another player)?

a) it takes a minimum 45-60 seconds to turn off whatever else is on, if anything, and fidelizer in Pro mode, get their website opening out of the way, and then go back to the player and start the music (in Audiophile mode, fidelizer's install just ran on and on, except when JPlay had been part of startup, then stopped);

b) since fidelizer kills the player's volume control, time has to be spent adjusting (Window's) Sound Mixer, hoping to get close from memory;

c) since fidelizer does not show in processes or services, doing more than one comparison requires reboot and starting all over again (~2-3 minutes minimum?);

Under these conditions, I sense a difference with non-fidelizer vs. fidelizer, but it's hard to tell for sure or exactly what it is. Likewise, with JPlay (trial) vs. fidelizer, I sense that JPlay is more "atmospheric" than fidelizer, while fidelizer's tone or pitch is lower (something bothering me about JPlay is with its increased atmospherics, it also seems to raise the tone about "1/3" octave).
No problem here with jremote in audiophile mode with fidelizer and jriver.

Now that I have used it for a while I can’t stand to listen to music without Fidelizer running.
Anyone running this with foobar? Any problems?
It works great and I use it with Jplay. You can use both as I do...
Version 6.2 released and you can buy Fidelizer Pro for better and permanent optimizations. :)
Do I need to open JRiver MC within Fidelizer each time for the optimizations to be implemented, or are these tweaks saved from the initial running of Fidelizer?
Run it before you open JRiver then open JRiver.
Since releasing Fidelizer 6.7, I noticed there're two types of computer audio setup. The first one is ordinary computer setup for better sound like most of normal people would. So Fidelizer 6.7 improves optimizations with consideration of common environment where security and user account control are working.

For another type of computer audio setup, it does nothing but playing audio. No security software installed and user account control is disabled completely. This kind of computer setup has better audio performance but be more vulnerable to security threats. With changes in Fidelizer 6.7 release, the overall performance is reduced along with security services that need to be turned off through external patches.

To make the most of both worlds, we need to find middle ground where it clearly separates between those two. In this case, Fidelizer 6.8 will check user account control's status through registry named "EnableLUA". If you disable user account control and set "EnableLUA" to 0, Fidelizer will apply optimizations without security concerns. It will also disable security services so you don't need external patches for this release.

Changelog for version 6.8

-Added Windows Defender, Windows Firewall, and related services back into stopping services list if User Account Control is turned off completely
-Added User Guide in download package
-Fixed failing to apply some core optimizations features due to service dependencies
-Improved process optimizations handling with User Account Control

-Added Windows Defender, Windows Firewall, and related services back into stopping services list if User Account Control is turned off completely
-Added User Guide in download package
-Fixed failing to apply some core optimizations features due to service dependencies
-Improved process optimizations handling with User Account Control

-Added Windows Defender, Windows Firewall, and related services back into disabling services list if User Account Control is turned off completely
-Added User Guide in download package
-Fixed failing to apply some core optimizations features due to service dependencies
-Fixed possible errors on machine running without logging on some services based platform
-Improved process optimizations handling with User Account Control

I also added user guide document and fixed some other bugs too. Some people who failed to notice the difference before may find it positive this time because I solved service dependencies bug on some machines now. Let me know if there's anything need to be fixed so I can make a bug-free stable release before Windows 10 comes out.

I tried free one about 6 months ago and loved what it did to max soundstage and control bass but found the vocals a little harsh. I tried it today (Version 6.10) and it seems a lot better. Actually I am really drawn into the music more and find myself listening longer and really enjoying the system a lot more, like I got a new componant. Wondering if the pro upgrade would improve even more. I like the simplicity of this using audiophile mode, extreem was too glaring and harsh. Great gift to the audiophile community! Thanks
Thank you for your feedback, Mr. Groundsource. I love to help computer audio community growing without spending big bucks on methods that don't really help most people.

The improvements shouldn't disappoint anyone who loves free version. You can read on reviews, testimonials and check on other forums for more feedback.

Fidelizer Pro also received Realsization award from 6moons recently. This award guarantees for its extreme value for cheap stuff that works so well beyond the price. It's the first software ever and cheapest product that receives Realsization award.
With the developers help- "windowsX" I have now been able to download Fidelizer Pro. I am not computer fluent and so a command to download Zip Unloader 20 for additional money confused me. Like what Ozzy described in an earlier post. This worried me. Also Finding the Fidelizer Key to enter to pay was confusing to me. And no you do not have to buy WinZip 20 to make this program work.

But after buying the Fidelize Program for $ 69.95, the developer via E mail guided me how to download the program and gave suggested settings to decrease drop outs. My application is streaming from the PC computer to an external Antelope DAC and then to the amplifier.

Bingo!  A much improved soundstage, better bass, richer harmonics.
This is a real keeper. Less money spent than rolling a single tube and a much greater possitive effect.

Absolutely worth buying the program. I hope The developer- WindowsX comes up with a click to buy, download occurs, reboot computer way to get the program into everyones system.

I also hope my fellow audiophiles will pony up and buy the Pro program after first downloading the more basic Free program.

David Pritchard
I have downloaded the free version. Will be trying in a few minutes. Anyone with very recent experience on this one?
I find JPlay inconvenient to use and the people behind this software have a pretty shady reputation if you do a bit of research.

Fidelizer, on the other hand, works well and the guy and service behind it is top notch.
Interesting @jaybe .
Very recently I found about jPlay and wanted to experience it in my system. I know about JRiver calling jPlay as a hoax. But many reviewers and folks also swear by jPlay. Some of them find it better than Roon. I had not read anything abou that "people behind" jPlay. Can you share some links?
@milpai I agree Jplay can sound pretty good.

I cannot provide links because I waste no time on this type of activity. Try google or search through other forums although you won't find a lot but it's there. 
@jaybe,I demoed the JPLAY and like you I found the playback pretty inconvenient. I could not focus on the sound experience due to the playback issues I had while I was trying to compare it with the the Foobar2000.

This is a great thing, I think everyone feels this information is very valuable, thank you . Check my Blog MakeMKV