|Here's what I would do:|
1- Install CCleaner Slim and get rid of all the excess junk on your PC.
2- Install Malwarebytes and remove all it finds
3- Install Avast Free and let it do a bootscan on reboot and remove all it finds to the chest.
All these are listed on one page in my sig and are totally free working software.
If that doesn't remove your problem, try the rest of the cleaners listed on that page. Let us know how you make out.
I don't know which AV you are using, but remember you can only run ONE AV at a time on a PC while you are on-line. So if Avast fixes your problem, you could disable it, or you could disable your present AV.
Some HELP in posting on Computing.net plus free progs and instructions Cheers