Changing PC resolution?

Have a desktop PC w/windows 7 which I use to stream music to my downstairs system. Comment was made on this forum that SQ can be improved by switching PC to 64 bit. I can't figure out how to do this. Is this something I can change within my PC via a setup menu or is it something I have to buy and install?
Maybe the comment you read referred to a difference between the 32-bit version of Windows 7 vs. the 64-bit version of Windows 7. In that case, you would need to buy the 64-bit version. Given the choice I would run 64-bit, but I still run XP 32-bit personally.
You may find your answer here:

With Mac you simply hold down the 6 - 4 keys simultaneously when restarting.

Hope this helps.

OUTSTANDING!!! Thanks, Mark. My computer is already running at 64bit. Now I can sleep at night.