I have the DAC w/ the USB port, now what?

I bought an external hard drive for my music.
I got a Benchmark pre-amp DAC with a USB port.
I have not yet plugged the DAC into my PC.
Do I need another device or a software program to hear my music through my Hi-Fi system? If so, what software do you recommend?
It's a PC running Windows 7.
The most common choice for software to manage a music library is iTunes, but if you are a perfectionist about ripping your CD's to your hard drive, the iTunes error correction does not do as well as others. EAC (Exact Audio Copy) does a great job at ripping, and I think is still freeware. You will still need some kind of library management software though. I'm not a PC guy so I'll leave it to someone else to point you more specifically to alternates to iTunes, but as far as keeping your library organized, iTunes does a pretty good job. There may be something better for PC though.
It's a PC running Windows 7
Windows media player
Buy a Mac Mini and use Pure Music which makes Itunes think it is playing the music.
All you really need is good windows player software that's bit perfect. Take a look at Fubar Player... it's good and free. Also, the J River Jukebox... it's free and the J River Media Center... it's very good but costs $50.00. Use the WASAPI driver.

"Buy a Mac Mini"... Why???
You already have a computer and a good DAC!
Pkubica, all I can say is that I used to have a Windows server and used Fubar and Exact copy. I don't believe anything about being bit perfect, as the Mac, using Itones and Pure Music killed the Window/Fubar combo.
Tbg... if that works for you great! I never said it didn't. However, here we have a person who hasn't even plugged in what he has already. He has a computer and a DAC, let's give him a chance to try it out and get his feet wet first. Maybe the results of his current equipment and a Free solution will be just what he needs/wants.

This is a community where we all learn by trying. Please consider giving people a chance with what they already have and let them learn from it. Throw it all away and start over is not always the only option.

With all due respect...
Pkubica, I cannot argue with you.
Use free iTunes and $50 Rivers Media Player which lays over it and will play anything.