I don't have that problem. I don't get any pop ups ever... except a small window sometimes telling me tracking cookies have been detected and removed... it goes away on its own.
I have active Norton 360 (anti everything) running in my computer.
If you knew as much about computers as I do you would realize how very unsafe you are online. Use common sense and spend a bit on anti virus software.
It sounds like your computer has no anti-virus and the windows program is warning you or you are already infected with a virus or trojan that is trying to sell you something.
I suggest you finally purchase some anti virus software. Registry cleaners are mostly a scam. Windows 7 comes with a registry cleaner.