I think I may have an adware virus on my PC.?

The google browser is painfully slow. The browser bar keeps changing to say things like 'transferring data from googleads.g.doubleclick.net' or 'waiting for ff.conextra.com' or 'read platform O.twitter.com' amongst lots of other things. Is this adware?? I'm at the end of my tether. Can someone please help.