Mac os 9 bomb?

My grandpa switched his os from osx to os9 and immediately the computer doesn't startup and a bomb appears on the screen. Has anyone encounter this before?

Mac os 9 bomb?

Nope. But after again I don't have Mac OS 9 installed on my Mac. Maybe something surrounded by OS 9s System folder is messed up. I wouldn't know how to troubleshoot it, sorry. You can reboot to OS X while holding down the option push button and choosing OS X.

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