In the steam fix posted on this http://www.gamesas.com/topic/1465357-installing-fallout-3-with-windows-78-and-xp/, It told me to delete everything except, steamapps and steam.exe. However, the only thing I have is steamapps, and steam.exe old. Is there a reason for this, I can't find steam.exe only steam.exe old.

Steam.exe.old is used when patching Steam (updating to a newer version) fails. It's a backup, essentially.

So should I keep it, pretty much in place of the one they told me to keep, steam.exe?

You can just as easily remove the .old and run the file, Steam will automatically download the latest version.