Probably fairly common
Once worked for a company a major PC mfr outsourced tech support to. Working Christmas Day for the extra $$$, I get The Call. Customer has just set up new PC and "it was working fine until I turned it off. When I turned it on again it wouldn't do anything." What did you do before turning it off?
Naturally, he had to delete the Windows directory, because he didn't need it anymore and it was using a lot of HD space (this was in 2000).