Sometimes a problem can be handled by doing a System Restore- but that is usually when something you did made a change in the system, such as an update, uninstall, install or download. That's why it best to create a new Restore Point before doing any of those things.
But in suspected malware, don't look for a fix by restoring- that will seldom change all the files or setting back to the way they were.
However, all pop-ups aren't malware and most pop-ups can be prevented. It's not clear if you're using the Mozilla Suite which has a browser or the Firefox browser which is freestanding, but from the Mozilla Org. FF has a pop-up blocker that can be set by going to Tools> Options> Contents> click to CHECK 'block pop-ups'. If there are sites you want to allow, type the URL into Exceptions.
The Google Toolbar also has an excellent pop-up blocker. There is a Toolbar for both Firefox and Internet Explorer. If you're not using any pop-up blocker at all, then you will get them.