Windows 7 Clean Install and Formatting

Ive been having many problems after downloading a file in Windows 7 64 bit Ultimate. The file wasnt a virus it was a game called cabal and ive played it on vista perfectly. After downloading that file 7 would crash if I hovered the mouse anywhere near the file. I had to boot in safe mode to delete it. Now after this the whole OS felt clunky and ran slow, programs would hang and firefox would hang the most. I put in my 7 disc (this is the full version not upgrade) and turned the pc off, booted from cd and deleted all the partitions including system reserved. I made a new partition and hit format and it took literally 3 seconds... Now remembering back to XP it took at least a half hour to do this. Is that right?

Well I finished that clean install and the problems still persisted among other new problems arising. So I did the same thing again, doing another clean install.

Same problems even worse.. So I wipe and install again and it is still slow and running clunky. I have given up on firefox cause it (not responding) so much its unusable. And Now Its mini crashing again. ( Where the start bar will disapeer and the desktop is frozen then everything refreshes you know?)

So Im getting on end here and want to solve this cause I am sick of wiping and reinstalling my college software which takes over 14 hours to install...

Can anyone please help me?

Im thinking its a bit of that file I downloaded still there not getting removed when I format etc. My friends had problems downloading that file in 7 64 bit too but it wasnt anywhere near this bad.

Thanks in advance.

Hey I gave up on installing the file that messed it up. I dont care about installing it now. So no I havent downloaded since the problems first happened. Also I use ccleaner, spybot, and microsoft security essentials.