BleepingComputer.com: Windows Wont Load After Log In

Hi,
So first of all Vista has been working fine before for a long time until now and no my computer was not upgraded to Vista, it came with it. The computer will turn on perfectly fine and when i click to log in on the welcome screen, vista wont load. So i went to safe mode and booted there but it took awfully long to load explorer and everything else and also task manager will not show up but its little graph icon shows up in the start menu and the CPU seems to be fluctuating constantly from 1-100 percent. I've also tried system restore to 3 different points with no success but one point which is the point of the date in which i started having this problem wont succesfully restore as in it will not complete, it freezes in the middle of it. So i tried to install HiJackThis but it wont install and i thought that maybe installation of the On2 VP7 codec was the problem and when i try to run its uninstall it wont let it uninstall. So my question is how do i get my computer to boot normally again and fix this problem?

Edit: got task manager to open on a reboot but nothing is showing in processes or anything. CPU seems to be running normally too but still everything is very very slow and logging in on safe mode still takes forever and logging in normally would probably take twice as long.. resource monitor shows that CPU usage is at 0-1 percent and used physical memory is only 39%. So i do not know what is at fault. Should i keep trying to restore to that date that takes forever? Even after hours of leaving it to restore at that date it never finishes but could it? any help would be greatly appreciated.
Thanks.
I've again also tried with msconfig, disabling all startup apps and messed around there but nothing helped.
more: i tried unzipping Startup List but it was taking awfully long only to give me an error message saying it couldnt unzip Error 0x8007045D because of an I/O device error?? i dont know if that means anything but maybe. Edit edit: I get that same I/O device error after i run that specific dated System Restore... please any help would be great

well since nobody has helped i just ran gateway system recovery with backup and it backed up all my personal files but i still have a problem, Vista now runs horribly slow, just as slow as before but at least it lets me log in.. so i dont know what the problem is here any help is great.

Did you run the complete "restore to factory state" system recovery? If so, then it could be that your hardware may be failing (if not, then there's lot's of other causes). I'd suggest downloading a free, bootable diagnostic from the web site of the manufacturer of your hard drive.

meh well i ran a whole restore to factory state but it created a backup folder and wont let me delete things in that folder even after messing around with ownership and properties of the folder.. meh everything else works fine other than having 10gb wasted off nothing. thanks for your help though. Turns out my harddrive had a problem.