iMac 27in 2013 prank

[Auburntycer]

I am needing info on how to make my imac seem as if it is unbootable or has a fatal error but that can be done and simply recovered by time machine back up. The person the prank is for I Mac illiterate and jus need them to assume it is broken in some way

 

[robotica]

Don’t do this. Pranks are not funny and you could genuinly ruin his computer.

 

[signuphere]

Doesn't sound funny, just wasted energy.