Got a virus on my computer how do i get rid of it, HELP!?

I have downloaded an infected program or virus that my antivirus software (AVG) can't detect it and the virus wont allow me to do a computer system restore. I know that I have the virus because videos on YouTube started to be choppy or just stop and ads are pooping up in places they never use to. All the ads are those scams for lower insurance premiums etc.... How do I solve this?

Already you have installed the AVG antivirus as the virus was not detected by the antivirus, may be that is not a virus might be Malware or Trojan. AVG free edition is limited it doesnot have all the features, if you afford to buy, get a full version of anitivrus or if you are connected to internet buy internet security my suggestion is to get Norton Internet Security.

I already installed and faced this kind of problem with many free antivirus and used to install the trojan remover and malware remover...etc including this antivirus. What happened is system getting slow down because 4 to 5 security softwares are installed in my system. If you got internet security software it optimzes your system to function properly.

If you want to do system restore, go to safe mode and while booting press F8 choose safe mode from the list. Follow the onscreen instructions to do system restore. Ads are pooping out because some click through software might be installed in your system go to control panel find in the list and uninstall them.