The behavior you are seeing is consistent with malware being on your computer.
There are three products listed below that are free for non-commercial use, but there are certainly many others you may try. No one will be able to tell you exactly which product will be the one to work for you, as there are so many variants of malware that produce the same symptoms, it is a trial and error process. Be certain that you update any definitions for any products you use, immediately prior to scanning. You will need the latest updates the vendor has available.
Suspicious Results and Strange Behavior: Strange pop-ups, toolbars, redirects, or results (anti-malware product list)
Malwarebytes.org
The home of Spybot-S&D!
Ad-Aware Free - Download security software for spyware removal - Lavasoft
Good luck, I have not been able to get my old computer restored to load google yet but everything else is working. It was an older one so I purchased a new one and use the old one for achives, as time permits I will remove files and replace those need on new cpu.