Get a good Antivirus thats not Norton. (Besides Rogues)
Like BitDefender, Kaspersky, McAfee, or AVG; Best recommended Antivirus software.
And get a Registry Cleaner/Repair/Fixer. This is likely the cause of you're errors.
If you're computer is laggy: You have a Replicating
WormIf you're computer is missing files: You have a
VirusIf you're computer is displaying pop-ups such as ads: You have
AdwareIf you're computer is showing odd files you dont remember downloading: You have a
Vulnerability or a
Trojan VirusIf you're computer has other side-effects besides the ones shown above: You have
MalwareWhen you find you're Virus name; search it up
here at Symantech. Please note that Antivirus's Virus names are sometimes diffrent, thus you may not find the virus name you are looking for.
I would recommend Kaspersky Antivirus/Intenet Security sence it detects Known, and Unknown Viruses using its Proactive defence.
When you find the file, please send it to me. I will examine it with my Antivirus Software, unless you got the Conficker.c Worm.