Daisuke's answer doesn't make sense because this context talks about something that the user is NOT supposed to do--i.e., if you were to install....

The correct translation uses neither when nor if--an overabundance of such construction indicates a too literal translation of all those 場合, 〜えば, 〜たら, etc. Japanese constructions.

Installing the ?board? in a system with different settings triggers a parameter error and lights this LED.

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Note added at 2002-09-13 03:11:19 (GMT) Post-grading
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In my list of Japanese if/when constructions, I forgot 時 and とき.

Watanabeさん、Maynardの答えをぜひ読んでください。まだできるのであれば、訳をぜひ直してください。