delete pop up windows

[mariap]

how can i delete unwanted pop up windows of previously visted websites?
Everytime the computer is in no use on standby (let's say for 15, 30 mins), when i come back, it has pop up windows that i do not want anyone to see. Can i delete those for good?

[JoshPerkins]

This maybe a cause from spyware or malware.
Try scanning a virus scanner (AVG Free 7.5 works good)
Running a Spyware check (Spybot is also good).
Tutut Mariap, shouldn't be going on those sites!

[mariap]

Thnx. I don'tknow about IT, but would this solve the problem? Isn't any other option through "internet options"etc?