Genuine Windows Vista

IIIT's Legal Volume Edition (Remember the legal XP we use?) from MSDN Subscription of Vista is Windows Vista Business N edition. Being legal you will get Windows Genuine Advantage (Whatever that means). Just install, boot and activate your windows entering the key provided.
The Business edition of Vista scraps out some number of softwares (which are all included in Ultimate edition) which are:

Windows Media Player 11
Windows Media Center
Windows DVD Maker
Windows Games: chess, poker, blah, blah
some more may be...

Use media player 11 setup for xp and it will download some 100mb patch for it and you will be good to go if you are a windows media player 11 fan (I am btw) else you can always use winamp and vlc/mplayer.

Now why am I talking about Vista suddenly? Answer: DirectX 10 Games. And if IIIT has a legal copy for its students, why not use that, right? (get the DVD from server room or ISO from me)

After installing all drivers and crap you should notice that, Vista doesn't (can't) come with newly updated DirectX 10 so get it from M$'s site here.

If you have a Nvidia 8XXX series card or AMD's HD 2XXX series card, you would surely like to check out if you are up and about for DirectX 10 games, so get the Lost Planet Dx10 Demo (you can get that from me).

I checked it out on a Nvidia 8600GTS and here are some screenshots
The game has nice motion blur and depth of field, nice post processing effects.The game is superbly heavy; Though 8600 is not a good card, above screenshots are for medium settings only.

Note that if you have a DX9 card and if you try to run the above game in vista, it will crash. However this is specifically for this demo only. Upcoming games for Vista (Crysis, Hellgate London, Gears for War etc.) should run on Vista with DX9 and DX10 cards both.