Is this keyboard USB or PS/2?
Have you tried using a different keyboard on your computer? If not, do so.
Have you tried using your keyboard on another computer? If not, do so.
What programs open up? Does it happen at any time or only while browsing the internet?
At this point, without much to work with, my guess would be that your Ctrl or Windows key is sticking. Answer the above questions and we'll see what we can do.