What can I do to improve my computer?

I am currently running a Dell computer with windows 7 to my PS Audio PW DAC II via cat7 cable.....using the bridge. I am waiting to either get the new PS Audio Silent Server (when it comes out) or a MAC Mini to use as my source. Until that time, can you guys recommend some things that I can do to improve the sound from my computer? Are there programs that will help? Any settings I can change?

The computer is just a laptop that is used vary rarely by my wife when she needs it (maybe once a month). I would like to get the best sound out of it that I can while I wait for the other options mentioned above.

Thanks
Jeff