Having moved to new hardware, a problem I was having has gone away. What should I do with the question I raised? Delete it?
If there is an answer with upvotes, you cannot delete it. But if there isn't any answer or the answer is very short (which can be considered as poor answer by the system) You can delete it.
For the answer to the question, "Should I delete?", I'd say, yes, You should delete the question, if you can,Because, there is no way to test and verify the answer now.
But, If you still have the old hardware and you can test answers and you believe the question will help future visitor, in that case, You should not delete the question.
Flag the question to be closed as "Too Localized" and we'll have the question closed.
I'd say you shouldn't delete it unless it was very localised (as per what Marco says about "too localised"). If you can still verify an answer, or if an answer is obviously correct without testing (but beware of the "obvious", often "obvious" means "speaker is not thinking" rather than "speaker can work this out perfectly without testing"), then mark it correct. Otherwise leave a comment about your inability to verify.
This way it may benefit someone in the future. I've never asked a question on the stack exchange sites, but I've had my questions answered by them hundreds of times, precisely because it was someone else's question some time before. Also, finding the answer to my question when it was someone else's question 5 months ago, is much faster than asking and waiting for an answer.