It is not so much that you're running defrag as it is disk usage. Anything
that heavily accesses the disk can eventually cause wear and tear on the
mechanisms sufficiently to shorten disk drive life (even if slightly) when
run excessively. You can get the same effect by constantly running chkdks
or other disk utilities far more often than needed. But don't let that
slight concern prevent you from running defrag appropriately (when the
defrag analyser says you should defrag). These are reasons why folks should
maintain a good backup plan. Hard drives do eventually just wear out even
when using best practices. I have some that have lasted many years and I
have had some that only made it a year.

"rick s" <ricks@discussions.microsoft.com> wrote in message
news:4C4390A7-08CB-4E70-9695-FF9880DA1801@microsoft.com...
> Someone told me that the more you run disk defrg the better chance of
> destroying your hard drive. Is this true?