I had this problem yesterday and just wanted to share, I have not seen this before so forgive me if it is common knowledge.

I wanted to install Monitor INF file for a Dell 17" flat screen monitor because I was getting out of range on screen sometimes.

I was able to find the Dell driver from Dell but it would not install. It kept asking where the drivers were located and I would browse to them and it would see the files, I would click ok and it would ask again where they were located - never ending loop. I dug into windows generic INF files to see if it might be a header problem (it wasn't) and I realized all the INF files had short names. I'm guessing INF files in 98 need to stick to 8.3 naming format. I renamed the .inf, .cat and .icm files then edited the .inf to reflect the naming changes. Installed like a champ, problem solved.

Maybe this will be of use to some.