Hi,
Get a friend or use another computer to download these two programs to a CD
http://www.freedrweb.com/
http://www.malwarebytes.org/mbam.php
Then See if your computer will load into safe mode,
Once in safe mode install and run {one at a time} the two downloades
Start into SAFE MODE
1/As your computer starts but before Windows launches, press F8 repeatedly.
2/Use the arrow keys to highlight Safe Mode, and then press ENTER.
3/If you have a dual-boot or multiple-boot system, choose the installation that you need to access using the arrow keys, and then press ENTER.
Note: If Windows launches before you can choose a safe mode, restart your computer and try again
PS/ Sometimes it maybe the F5 key