My friend cannot open his Steam folder... Help?

First off, he is running Vista, which I have no experience with. Second, it is his mom's computer, god knows what she has done to it...

Anyway, my friend recently bought Killing Floor and has been trying to join my server. I have been trying to fix the problem by opening up his Steam folder.There is only one problem... THERE ISN'T ONE... At least not one that we can find. I've tried the places where I would normally look. (For example: C:\Program Files (x86)\Steam) Please note that this is for Windows 7 and I'm sure it is a slightly different address for Vista. We tried the regular Program Files folder, no luck.

We also tried to right click one Killing Floor to locate the folder it was located in. However, this option would not work on ANY of his steam games. (It worked fine with everything else.) Also, we tried using the search bar to locate the game, no luck there either. The game isn't even found when typed in the search bar. We did find 1 Steam folder but it was a scrambled mess. It was nearly unrecognizable, full of random word files and apps that I've never seen before. There were no sub-folders except for a cache with 2 small files in it. No games or anything.

I'm not sure what to do at this point. My friend is becoming extremely frustrated at his inability to join ANY server in Killing Floor. He's starting to give up with the whole process. I feel guilty since I had convinced him to spend the $10 to buy the game. If anyone has experience with Vista or anything related to this problem, PLEASE HELP.