Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Hi I am in an emergency situation right now. I DO have full backups of everything, but I am trying to avoid a complete reinstall of the OS and AD. I have a simple server with one drive that was set to Basic. I searched and searched for problems with converting it to dynamic, but everyone said to make sure I have a backup and just do it. So i did it, and now the system is stuck in a reboot cycle.

After researching this for hours it looks like most people boot to another OS with the failed drive in another slot, then run either dskprobe or a hex editor and change a particular hex number from 42 to 07. This tells the disk that it is basic, and I should be able to reboot.

I have tried dskprobe, and hex editor and TestDisk and in all of these I receive some form of error when trying to change this value. Dskprobe gives me a "Incomplete Data Write / Error writing sectors" error, the hex editor (HxD) gives me "the media is write protected", and TestDisk gives me similar.

Does anyone know how I can get past this? It seems like I am very close, and somehow I just need to unlock or un-protect this drive.

FYI - the drive is a 73GB 10K SCSI with one partition on it that has Windows 2003 Server. I just want to be able to boot that again!

share|improve this question
Why don't you tell us what type of reboot cycle it seems to be stuck in. Are there any messages on the screen when it boots/reboots? – joeqwerty Mar 13 '11 at 19:46
I have to ask, with a single drive why do you feel the ned to convert it to dynamic when there is no benefit in doing so? – John Gardeniers Mar 13 '11 at 22:01
Actually there are 2 drive bays on the server (PowerEdge 1850), so the intent would be to have 2 dynamic drives and set up a software mirror. There is no hardware RAID in the server, so this was the only type of fault tolerance I could think of. Since this whole thing didnt work, I will not be converting it at all now. I am going to use Acronis to image the drive and if the drive fails, I will use that image plus our nightly backups for the restore. – charnley Mar 14 '11 at 15:07
up vote 3 down vote accepted

I figured it out. Here is what I did:

I was booting to Win 2008 Server, and using the utilities from there. Since I was getting the write protection errors, I thought I would use diskpart and see what I could find.

In diskpart I selected the disk and looked at the settings - it showed the disk as read only. So I ran the command:

attributes disk clear readonly

This completed with no errors, and then I ran dskprobe again. This time when I saved the hex change I got no errors! I turned off the server, put that disk back in the original server and it booted up fine.

share|improve this answer
+1 - Glad you got it figured out – Mark Henderson Mar 13 '11 at 22:15

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.