Malware HELP!!

My computer has been infected with malware for the second time. the first time it fixed itself and went away. this time its worse. there is a red backround screen that goes over my background that can be closed down but comes back. Rogers ( internet provider) says that theymight call the police because we have been going on porn sites. No one has ever gone on those. Please Help!

 

you might want to click on the red triangle at the top and ask to move your thread to the security forum.