We have a NT server running IIS with secured website....
All computers but one have no problems accessing it.
This one pig... when you get to the site you get the log-in screen (we are using NT security for authentication) as expected, type the user name and password, and then it just kicks you back to the login screen and after 3 times says authorization failed.

I've tried repair function, as well as a few other sites on different servers, all no go... any ideas?
Win95 OSR2, IE 5.5 SP2 128 bit encryption.

Couple of things to check here:

Have you tried accessing the site by direct ip? (for example http://192.168.0.1 or whatever it's IP is)
Does that work?

It may be a group permission issue as well.
Also try going to a machine that does work properly, rename it to the name of the machine that doesn't work, then see if the problem exists. If it does it tells you the problem is related to the netbios name of the PC that doesn't work.
Then go to the PC that doesn't work and rename it temporarily to one of the PC's that does work. Then try it.

It could also be related to security settings in IE. Temporarily set the security to the lowest setting in IE and try it again. If it works you'll need to figure out which setting needs to be modified (though you'll likely not want to leave the security settings at minimal).

Also if you are just in a hurry to fix the problem and don't want to spend a lot of time on it you could just clone one of the working PC's, then redo whatever drivers need to be redone, then rename it.
Good luck.
Jimbo