Hi i hope you could help me with this humongous problem i'm having. It started after i downloaded some application. my antivrus (mcafee 9.0) shutdown and through a process viewer i could see it kept trying to get back on(since it was using up all of CPU) but it couldn't.
task manager couldn't be accessed , it said it has been disabled my admin.
system restore was disabled! i tried restoring to "best known config" through the F8 option while booting, no luck. And then all of a sudden it boots to the login part and once i login my wallpaper loads and nothing else happens- no icons, no task bar, no response to ctrl+alt+del. only mouse pointer(which moves normally).
The WORST part: tried using safe mode and every time it finishes loading files my system restarts. tried all 3 safe mode options in fact tried all F8 options.

Now i loaded a new windows in a separate windows folder so that my old windows files are not affected (With the hope that sometime i could possibly go back to using that). i ran a virus scan(mcafee) through this and quarantined all detected viruses. However, my original windows still shows the same problem- no desktop, no safe mode etc. i have several important files which i cant lose so formatting is NOT an option. Reinstalling windows is also NOT an option mainly because Ive reinstalled windows twice in the last 4 months and i don't want to give into the virus this time. And yes, once its fixed i am switching to a new OS. Windows is a nightmare.

Would not getting a reply mean this problem has been solved before or would it mean i should give up?

I honestly think none of us know what to tell you here. Since you cannot get into Windows it seems you cannot run the programs needed. It sounds to me, I could be wrong, that key windows files have been damaged by whatever it was you downloaded or the attempted clean up. I cannot say for certain. Your only option may be a reformat.
Have you tried a repair of the affected Windows? The repair may keep the files you wish to keep but correct the damaged os files.