Log in in Vista 64 bits

Hello All.
I use an online school website to attend online classes. I have been using IE 8 for a while and Windows Vista Home premium. My wife uses the same on her laptop, but a different log in name and password. Just last week, Everytime I type in my log in name and password on my laptop, it takes me back to the same screen, log in and password. But when I insert my wife's log in name and password, it accepts it and lets her in. I tried my log in name and password on her laptop and it accepted it. I downloaded Firefox, and it accepted my log in info.. In other words, it is only my log in infor that will not be accepted?

I cleared the cach, history, cookies. no good.
Help is appreciated

 

Anybody would like to take a stab at this one? I still can not use IE to log in, I have to use FireFox! :eek

 

Try IE8 with no add-ons.

Try also in safe mode with networking.:wave:wave:wave