Slitherine

No stranger to installing gcs successfully, just wasted most of the night trying to install 45 West.

When trying to install get a message that the program is already in use by another program

What the heck is going on, help please

If you've already tried rebooting, perhaps installing while in Safe Mode would work?

Like alkafluence, I too suggest you to install the game in Windows safe mode.

How to start Windows in safe mode:
http://pcsupport.about.com/od/fixthepro ... e-mode.htm