How to know if PC contracts virus.

If you feel your PC performs peculiarly, possibly it is infected with malicious virus. Here are some quick tips about how you can detect and pervent:
-Keep your eyes open on any strange files which come out of nowhere. Usually those files are .exe type and their names are somewhat peculiar.
-Your PC is probably infected when you detect that anti-virus program or Msconfig or windows registry editor or any program installed don’t run properly.
-Watch out any sub-menu options of Windows Explorer menu are missing.
-Be aware that your PC uploads files over the net without your approval. Spyware or malware can grab your personal info and get it sent online.
-Install good firewall program since it can report on all outgoing activity and always update anti-virus program.