defragmentation problem

[Craig]

I am having trouble doing defragmentation on my D: drive
using Windows XP Home. I have a Sony desktop model
PCV-RS430G. When I run the defrag utility, it tells me that
I must run chkdsk/f on the drive first, but when I go to
the DOS command line and try to run chkdsk/f it says it
cannot run "because the volume is in use by another
process. Chkdsk may run if this volume is dismounted
first. All handles to this volume would then be invalid.
Would you like to force a dismount of this volume? Y/N?"
What might be causing this problem? And what does
"forcing a dismount of this volume" mean? Is it equivalent
to a reformat?

 

[Wm]

Craig: Forcing a dismount just means that if any
programs/utilities are using the drive that they will be
closed. Nothing bad will happen to the drive. You will
have to reboot afterwards to remount the drive.

 

[Guest]

Thanks. I solved the problem by reading some other
postings and was able to fully defrag in Safe Mode. The
defrag utility now runs fine in Normal mode.