Out of curiosity, does running disk defragmenter reduce the life of a hard
drive?
No.
How often should disk defragmenter be run?
There's no answer that's right for everyone. It depends on how you use
your computer and it depends on how much you use your computer.
You should defragment your drive when doing so results in a speed-up.
Here's what I recommend. Pick some arbitrary interval--for example
once a month. Defragment on that interval a few times, and assess
whether the computer generally feels faster after doing so. If the
answer is yes, defrag more frequently. If the answer is no, defrag
less frequently.
Repeat a few times, and you'll soon settle into a frequency that works
well for you.
