I had a spare 500 GB HD and I installed High Sierra on it using DiskMaker 7. I booted the recently bought used 2.3 GHz Mac Mini from the external Hard Disk and it booted properly. My only issue is the display. I cannot see the the top menu and even the bottom task bar is half visible. The configuration of the Mac Mini is 2.3 Mid 2011 Mac Mini with 2 GB Ram and built in Intel graphic 3000. I am using a 21 inches HP Monitor. I tried the various resolutions and also the default resolution but still I cannot see the top and bottom part of the display. After this display problem is resolved I will install this hard disk or a 500 GB SSD inside the Mac Mini. Also I will increase the memory. Kindly help me to solve this display issue.