Is this a virus? Whats going on ;_;~help

Ihave Windows 2000 Professional, and just like everyone else, I have a pop-up blocker. My pick is "Stop-The-Pop-Up," and it work(ed)s great to a point....

About two weeks ago I slowly started to get pop-ups...more and more they came. I then downloaded two other popup stoppers and run them...none of them are working now...and it’s getting a little out of hand...actually a lot.

Also when this problem started, my text size for Internet explorer changed at random without me doing it. Some times it would just change in front of my eyes to largest text size, while the next moment...it would change to smallest.

The next problem which started happen, the thing that is bothering me most, has to do with typing:

No matter where I type...if that is in notepad or a pager, my text on the screen will suddenly change to all caps without the caps even being on my keyboard...this will last a few moments until I just keep typing more and it will go back to normal...the same sort of deal happens if I am typing a word which has the letter "i" in it...my text will change to italics...or bold, for example, if I type a word that has the letter "b" in it...
...This is quite irritating because I am a college student and I have to type a lot of papers >.>;...so please someone help?

Thank you.

And I have ran NAV several times...each time a virus was not found -_-