There are two reasons:
1) Running D.D. nightly vs. monthly will increase your performance
by 1-2% at the _best_ [for average user, not a pro]
2) Defragmenting is quite a strain on your hard drive, and it should
be avoided unless necessary.
-MaxVT
Do you want to signoff PCBUILD or just change to
Digest mode - visit our web site:
http://nospin.com/pc/pcbuild.html