Street fighter 4 & another game help :(

Ah ok well normaly i do not have a problem on figuring out why a certain game doesnt work, but this time its kinda....ticking me off

My friend gave me his Street Fighter 4 PC game. And, i looked up system requirements and stuff and i should be able to run it. but for somestupid reason. It refuses to open, no matter what i do with it. Now if i try it on my Vista harddrive, it works fine on there, but i dont like vista because it makes the game require like double what i have...it still runs but...id prefer a 55~60 average framerate with it -.-

I wanna know why it wont work on XP tho the case it came in says it can run on XP all the website ive looked at ALSO say it runs on it. but it works on Vista, tho i have.. little more then half of what it requires?

The other game is another confusing case, its called Sonic Mega Collection PLUS for the PC. Yet again, i am forced to run this on Vista, it doesnt lag or anything but i dont wanna switch harddrives everytime i get an urge to play Sonic and knuckles if you get what im saying.

Can anyone tell me what the crap is goin on here?
thanks