Having replaced a 2010 Mac Mini with a new iMac, I used Disk Utility to erase the Mini's HD with a view to reinstalling the original OS from the original installation disk and to try and sell the Mac Mini. It is formatted to Mac OS Extended/Journaled. There was no additional GUID partition option.
However, the original install disk (OS 10.6.3) won't run and just keeps getting ejected. So I restarted using CMD-R and brought up the Mac OS Utilities window in recovery mode. Made sure the computer was connested to the internet. Followed the instructions to "Renew a new copy of Lion" (I'd upgraded the original OS from 10.6.3 Snow Leopard to Lion and then paid for 10.8 Mountain Lion - which is still shown in my purchase history on the App Store).
Enter my Apple ID and password and am presented with the window shown below - and no amount of trying again breaks the deadlock. I can access the App Store with my Apple ID on the new iMac.
The original Install disk is readable by an ancient Power PC iBook G4 - but not usable as it needs an Intel processor.
Any suggestions grateful received as to what one might do?
*SORTED* 
