Front Office Football Central - Program Installation Issues?

Ok, I'm having this strange problem I've never seen before, and I have no idea where to begin going about fixing it.

Last night, I went to install the 5th release of PS, since I hadn't done that yet. I downloaded the zip file fine, then went to install it...and nothing. It wouldn't install anything. It started the install shield wizard, asked where I wanted to put it, then immediately said it was finished. It put the PureSim 2005 folder where I told it to, but didn't put anything in it. I tried running it multiple times. I tried restarting, and then running it. I tried deleting the whole zip file, and re-doing everything. The same thing keeps happening over and over again. I had the 3rd release installed fine before, but I uninstalled it and then wiped it from my HD before trying to plug in the 5th release (which apparently I didn't need to do, from perusal of the PS boards).

System Specs -- Athlon 1.2 G processor, 256 RAM, GeForce 4 4600 (I think) Graphics Card.

Anything you guys could suggest would be great -- I've already posted this at the PureSim boards as well. I'm going to be at work all day, and I wanted to catch people's attention for advice about this before everyone went home.