yes...like Nicole says, the registry can be edited and cleaned. It is important to know exactly what the 'geek' says is 'installed'.

Do thos pop-ups look like this ?

If so, "A lot of "spammers" these days are exploiting the open NetBIOS port (139) on 2000/xP boxes to display this new kind of spam. They use software that uses the "net send" command to spam hundreds and thousands of IP addresses a minute. The only way to stop them is to stop & disable the messenger service in Control Panel | Administrative Tools | Services."

have you looked at all at those settings? If that is not the problem, we will have eliminated one thing, but you need to know.