Trying to erase and reinstall macOS to reset factory settings. Held down Command and R at Restart but computer just restarts and Disk Utility does not open. When I manually open Disk Utility, Erase option is grayed out. Please advise.
iMac 21.5″, 10.15
Do you have an Apple Wireless Magic Keyboard with rechargeable batteries? If so you can run it as a wired keyboard with its charging cable. That should let you boot into the Recovery volume.
Another issue with wireless keyboards is that you sometimes have to wait until you hear the startup chime to press cmd-R.
Something to try if you don't have easy access to a wired keyboard.
Erase and reinstall macOS
