Whatever you do don’t click on any pop-ups on your PC while your surfing around. It’s best to just close them out by hitting “X” in the top right corner. This article from PCMECH by David Risley highlights what can happen if you do click on these fake ads. I also had a similar experience with “XP Internet Security 2010” back in March of this year. Which looked like this:
What usually happens is that your machine will become infested with malware that will eventually slow down and make your computer a real pain to use. You should have it cleaned out as quickly as possible. The longer you wait the worse it will get. Worst case scenario is that you’ll have to reinstall your operating system. This is the extreme case and should be avoided if possible.
Here are some recommended software that will aid you in your battle:
Good luck and happy surfing!