Computer Things "Undoing" and Very Slow
So, I shut down my PC for the first time in awhile before I went to school today. I come back, and my PC can barely load up! I had something that made it so my mouse cursor and my Windows sounds were that of Vista, yet, they're reversed back to XP out of nowhere. I sometimes had problems loading into Windows because a lot of crap loads up at once, but, 90% of the time I could easily bypass it/it wouldn't matter. Now if I tried to end something using Ctrl+Alt+Delete it would lag, bad, and then finally work again, clicking start would cause problems, and sometimes it would freeze bad. I thought it might be HDD space but I still have 11GB on my C: Drive and 200 GB on my D: Drive, I'm still cleaning it up though.
What I've done recently:
Installed an M-Audio Revolution 7.1 Channel PCI Sound Card
Installed Fable: The Lost Chapters
Everything was working fine before I shut down... any ideas?