Have you tried to disable User Account control and see if that makes a difference when you try to install a program?
If not, then try a SFC (System File Checker) scan to see if you have any corrupt system files.
Type: CMD, from the results, right click CMD
Click 'Run as Administrator'
At the Command Prompt, type: sfc/scannow
This will check for any integrity violations and fix any corrupted operating system files.
Restart your system