Installing programs, and getting internal errors.

Hey guys I've been having trouble installing some programs and games onto my windows 7 home premium edition, Upon trying to install the game "Just Cause 2" i put the disk in my CD drive and it pops up asking me what do i want to do? and it says run autorun.exe and it starts, but once it starts the setup to the game, i get an internal error, which reads as follows. "Internal Error: Failed to get path to 64-bit Common Files Directory." Now i checked my Program files(x86)/common files is there. I checked regular program files there was no common files directory there so i created a folder and went ahead and named it "Common Files" for the heck of it.. alas the same error still happens.. i've done some research on it and got to somewhere where Microsoft said to check my UAC-filevertulization in my registry, and checked the event I.D its "2001", if that helps.. anyways.. any thoughts or am i screwed? lol