First at all, check what anti-virus company runs in your computer.
, <<you have Comcast and by such, you have installed Norton Anti-virus.
First you run Norton Anti-virus. Of course this step won't do much. But it is required, so you call Comcast and said what you have tried.
From here, Comcast will help.
You don't need to download third party software, you don't need to take your computer to anywhere.
Comcast service includes the removal of all kind of virus and malware.
The expert will ask you if you want to follow his instructions or, if you want to let him control your computer and he will fix the problem while you watch in the screen what he is doing, while he might explain his steps by phone.
You will notice that they do have the proper software and experience to repair your computer from outside attacks.>>
If you have other company for internet services, and this company includes anti-virus services, then call your company and they will take care of the problem. If you have an Anti-virus company that is not affiliated to your internet service company, then you may be charged for the service.
Don't waste money paying third parties that will do the same repairs that your internet service/anti-virus company will provide for free, because such services must be included in the Anti-virus contract.
And, do not download "free" software online that promises to fix your problem. Remember, nothing is free in this world, and these websites will install their own malware in your computer. Watch out.