need help please i already has avast and have turned pop ups off in the browser but i can't stop the popups. what do i need to download to solve this problem its driving me mad and making my computer run very slow i know its a virus but just need a good way to get rid

If your browser allows it and has not been hijacked, install and run this,top right hand side "download latest version" ..
http://filehippo.com/download_ccleaner

Then this Malware remover for all your Adds,"Free Version,

http://filehippo.com/download_malwarebytes_anti_malware/

Message me regards pop up blocker ..

Chrome Adblock?

And +1 to Malwarebytes, brilliant software.