Help on Mountain Lion Install

[gunlocators]

I have tried 3 times to install Mountain Lion on my wifes macbook and get below error I am confused. I installed it on 2 other macbook pros of mine fine and still need to install on sons iMac and other sons Macbook Air....

 

[CoreForce]

Many face this.

See here for possible solutions:
https://forums.macrumors.com/threads/1412338/