Error 5, cannot install program

[bakto]

I'm trying to install a program (game) and keep on getting Error 5: access is denied when trying to install to Program Files (x86). I did a bit of looking around and realized that under Security -> Permissions for Program Files x86, I'm missing 2 out of 7 permission entries that I've found under other normally working computers, both having to do with Admistrator. My list goes like:
CREATOR OWNER
SYSTEM
SYSTEM
Users (username)
TrustedInstaller

The other computers have 2 more entries, called Administrators(username). Is this my problem? And how do I manually add these entries?

 

[rgd1101]

right click on the setup exe to run as administrator

 

[bakto]

Running as Administrator doesn't work - to clarify, I can install this program without problems on other computers, and can even install the program to any location on my computer EXCEPT Program Files x86. The access error only comes up when I try to install to that location, confirming my suspicions that it has to do with permissions entries being missing for Program Files x86.