Honestly, if you're not going to play games on your PC, there's no reason to use windows. Ubuntu linux has everything you need out of the box + desktop effects that puts vista aero to shame, real big shame. I can run ubuntu 7.10 with 3d desktop and rotate the desktop cube at 40+ fps on an athlon tbird 1ghz and a ATI 9100pro.
Here's some videos on what desktop effects you can use:
http://www.youtube.com/watch?v=4QAu8pvD358&NR=1
http://www.youtube.com/watch?v=pn2F-y73Tnw&feature=related
Also, here's a video that shows you how easy it is to install:
http://www.youtube.com/watch?v=njv1A-bjnzw&feature=related
I would suggest at the minimum to download the ubuntu ISO and burn it onto a CD, you can actually boot into the OS FROM the cd without having to install it. Of course, it'll run much slower off the CD.
In the case you like using ubuntu, you can actually take your 600 dollars, buy a ps3, a second controler and a couple of games to go with your tv downstairs and still enjoy astonishing eye-candy on your PC without having to invest a dime into it. (Except perhaps the dime you'll spend on a blank CD)
IMHO, it is by far the smartest things to do as you'll be able to use word processing, spreadsheets, web browsing, bittorrent, etc... that comes pre-packaged for absolutely no money.
And if you do feel like playing games, you can always try out wine (Windows emulator to put it simply), dosbox to play dos games.
I got a nintendo, super nintendo and PSX emulator working flawlessly with USB controler on my computer.
For computer games, I got doom3, quake4 and Nexuiz working flawlessly.
Through windows API emulation, I got: Guildwars, counter-strike 1.6, source, hl, hl2, quake 1,2,3 , starcraft, diablo.
One that's highly recommended is Nexuiz, it's a FPS based off Quake1 engine. Although it's heavily modified and can be compared to UT2004 graphics or better. Very fun to play. And free =]