Cannot select Mac HD when reinstalling OS High Sierra
Hi,
I'm selling my mid-2011 Mac which has served me well. I've taken steps to clear it before I put it up for sale and I'm stuck on reinstalling High Sierra.
The system is asking what disk I want to use. The Macintosh HD is available to select but I cannot select it. There are no error messages. All I have to do is select the drive, but I can't. Only the keyboard is available and I've tried the keys which have got me to this stage: tab. space bar, arrow keys, enter. Nothing works.
Needless to say it's immensely frustrating!! Any help is much appreciated.
iMac 21.5″, macOS 10.13