Thanks for your reply.
Nodsu : thanks a lot. A simple answer, which I did not find out it by myself
SultanGris: You're right, although Firefox is better than IE, I prefer to keep my configuration as simple as possible. I keep cleaning my system even by editing the registry. That is the reason I use the default browser (IE) instead others (netscape, firefox, opera, etc). I never have any issue with IE (no virus, no spyware, etc), so I do not need anything else.
This ocasion was special. Somehow my IE switched the "text size" displayed. So simple to fix, that instead of checking by myself, I opted for posting this thread.
By the way, the firefox I used and I am still using this time, it is running from my flash drive, as a standalone program. That means, it is not installed on my HDD (my Zone Alarm did not detected any modification in the registry when I run it). How could that be possible? Time ago a friend of mine gave me these standalone programs on that flashdrive. I never though they would work and specially, that they would be really handy. I still wonder how they created them. Any idea?
Also, i did not like IE7, so I went back to IE6 for now.