Originally Posted by
tev9999
Reinstallilng the OS is the last resort. Most malware can be cleaned without damage to the OS if you use the right software.
Besides the fact that you lose all your files with an OS reinstall. Kind of misleading advice from planensimple who didn't mention this.
The easiest first step is to try to use System Restore to go back to a point where the computer was working well, then do all the antivirus/cleanup things mentioned above. You may have to start in safe mode to do this.