Check for unauthorized programs (or Malware) running on your system
If you suspect that you might have unauthorized programs running on your system, you should install HijackThis. Even if your system is running without issues, you should have this program handy in case something unexpected occurs. HijackThis will analyze your system for unauthorized programs. It is typically used to identify malware programs that are launched at boot time. You can download it from the HijackThis website.