This question https://diy.stackexchange.com/questions/3025/best-way-to-clean-pc-from-the-inside-closed is definitely off-topic for Home Improvement and was properly closed by the community. But should it also be deleted? I think in this case the answer is yes but I wanted to confirm before I went and did it.
Yes, as a general rule, off-topic questions should eventually be deleted (and already has). Generally speaking, there are two reasons a closed question might not be deleted:
- The question is being improved and might be re-opened.
- The question was closed as a duplicate but the text of the question is sufficiently unique as to provide a valuable entry point to point to the original question. See: Love Duplication