A complete and correct scan of your computer for viruses and other malware such as Trojans, rootkits, spyware, worms, etc. is often a very important step in solving problems. A "simple" virus scan is no longer sufficient.
How to Detect a Virus on Your Computer | How to Check PC Viruses and Malware | Best Antivirus Scanner
Many forms of malware cause or masquerade as seemingly unrelated Windows and PC problems, such as Blue Screens of Death, DLL file issues, crashes, unusual hard drive activity, unfamiliar screens or pop-ups, and other serious Windows issues. It is therefore important to thoroughly check your computer for malware when attempting to troubleshoot many issues.
It is easy to thoroughly scan your PC for viruses and other malware, but it can take several minutes or longer. The more files you have and the slower your computer, the longer the scan will take.
Download and run the Microsoft Windows Malicious Software Removal Tool. There are two versions to choose from, depending on whether you are running a 32-bit or 64-bit version of Windows (read which one you have):
