Defrag dfrgntfs.exe running in idle

looks like you have Diskeeeper installed. If so open it up then if this version 8 then click in the left hand side "Set it and Forget it" and find out if of those selections are running a Sheduled defrag. If do unshedule it.

No, Diskeeper is not installed.  The link http://www.microsoft.com/whdc/system/sysperf/fastboot/fastboot-winxp.mspx does not seem to address the question:

"QUESTION: How do I prevent the dfrgntfs.exe program from starting up automatically in the idle state?"

Ok then look in Control Panel > Scheduled Tasks
Do you see anything there pointing to derfrag?

Well you cannot run dfrgntfs.exe from the command line or scheduler, but I think IceRaven is on the right track. See this link:
 "19. Logical Prefetcher in Windows XP"  near the bottom of the page:
http://snakefoot.fateback.com/tweak/winnt/tweak.html

Well not offense but I don't think Prefetch has anything to do with defrag running on its own. Prefetch is there to sort have images of programs used in the past so the OS doesn't always need to go look for this and that when the program is launched. Perfetch is doesn't do anything about launching things on its own. Why dfrgntfs is running on its own is anybody guess. You can use third party defrag utitilies to schedule but the built in defrag utility does not have this capaciaty.

ICF will not close ports on its own.

Diseregard my last comment. I posted in the wrong question.

I checked the "Scheduled Tasks" and defrag is not listed.  Perhaps it's built into the OS and not an option to turn off.

I have read the tweak link provided, and I didn't find anything on disabling defrag.

I fixed the constant hard drive activity by disabling the CISVC.exe

Here is what I did:
Run Command > SERVICES.MSC > Rt click on "Indexing Services" >  Properties > Startup > Disable

Problem solved.

I awarded the points based on both of your efforts.  Thank you.

Ok yeah the indexing service can be a pain in the... well you know what. But as far as involving the defrag service, well something is kind of weird here. Defrag, at least the one that comes with XP will not jump up and be that prevelant. But then again we are talking about Uncle Bill and I guess at best anything is possible. :)

I just need to mention, that the "turning off prefetching" solution, which germanti brought up, works for my "unattended startup of dfrgntfs.exe" (which I tracked down with sysinternals.com's NTFilemon, because I also was wondering on my hdd's activity every now and then.

see also the very fine description at
http://snakefoot.fateback.com/tweak/winnt/tweak.html#WINXP_PREFETCH

QUESTION:
How do I prevent the dfrgntfs.exe program from starting up automatically in the idle state?

I have been looking for a solution to the same problem as Deming on my XP for over a year. I immediately tried the suggested solution of turning the "Indexing Services" off...but unfortunately the problem still persists.
Dell (who have no idea why defrag is running after 15 minutes sytem idle) are now suggesting I re-install the XP OS - which seems a bit drastic and may not solve the problem. I am amazed that this is a) not experienced by more users and b) the solution seems so elusive. I'm thinking of renaming defrag.exe so the autorun can't find it - but don't know what extra problems this might cause. Grateful for any ideas.  

And there's sometimes a happy ending...In answer to my own comment above, I also disabled the Log on profile in Indexing Services - as well as the service itself.
I also disabled Task Scheduler and again; disabled Log on Profile 1 for that service.
At the same time, I changed my desktop picture to a serene dawn over Cambodian temples...
One (or all) of the above have stopped defrag running now when the system is idle.
Peace and harmony are restored.
Thank goodness for this excellent forum.
Hugh.  

be interesting to know what triggered it..

in my case, I had just installed win xp sp2,
- I had gone through the windows setup and used L to delete the old windows directory and install windows. So documents and settings still had subdirectories of profiles from the previous windows version.
- I did rmdir /s on those subdirectories
- I also installed the dotnet framework exe. (so microsoft  keyboard layout creator would work)

I was running internet explorer when the process became active and my hard drive went very active. I stopped it by closing internet explorer, then tried renaming the file \windows\system32\dfrntfs.exe, but it came back because it was in \windows\system32\dllcache, so I renamed it there. Then remaned it in \windows\system32.  That worked.
I then lost internet access , restarted, and it was fine!

this solution iseems better than what I did! But it would be interesting to find out what caused it. Maybe others did similar things to me,  the rmdir /s on a profile directory e.t.c.