Saturday, November 19, 2011

As far as converting disks - the backup and system scan with TestDisk is overkill but of course it will work. The testdisk method is irrelevant to dynamic -> basic conversion - although testdisk is greatly useful if you have additional errors in the partition table...... I have converted many dynamic disks (working and non-working/non-bootable) back to Basic by changing the "Type 42" (dynamic disk) to "Type 07" NTFS as it says in the workaround section of "Microsoft KB article 913964" with a Disk Hex Editor such as (
  • " In the editor, find the 01C0 line. In this line, the third pair of numbers on the right is 42. Change 42 to 07".................
HOWEVER THERE IS A CATCH (and maybe why it didnt work for you). Essentially -
  • To sum up - If your 01C0 line says "42 A3" - That is the system reserved(boot) partition (the A3). If it says "42 EF" - That is the Windows install partition (the EF).
  • Hex-edit both instances of "42" to "07" (the third hex pair on line 01C0 and line 01D0).
  • This is necessary because only some simple Dynamic disks are created with 01C0 as the only partition.
  • With Windows 7 dynamic disks that contain the System Reserved boot volume(100MB), - The 01C0 line is followed by lines 01D0, 01E0 and 01F0 all having "42" in the third pair of numbers. The 1st and 2nd one correspond to your System Reserved and Windows Installation partition respectively. (The 3rd and 4th are the dynamic disk partition data info).
  • This is very reliable and I have tested it while writing this post.

Once you finish hex-editing, reboot, and the system SHOULD boot right up.

If you have line 01E0 and line 01F0 indicating "42" - change those to 07 as well - it will allow them to be removed- Disk Management will detect those 2 unused partitions (what was #3 and #4) in Disk Management (in the top portion they will show as Dynamic Missing Failed (one being 100MB and the other being the same size as your HDD) simply right click, Delete the two that have error'ed out icons with no name, Close out Disk Management, Re-open it. Now it will show up 2 more unlabeled partitions with sizes 0MB and 1MB (possibly having been given a drive letter showing up in my computer that shows as a RAW unformatted partition) ... right click DELETE those (0MB and 1MB RAW) And the process is done.

I have done this with much success. The Microsoft and most tutorials on the web fail to mention all 4 partitions (The most important difference that I listed is - if you use Windows 7 (it comes with a SYSTEM RESERVED 100MB partition being partition 1(line 01C0) and Partition 2 is your windows installation - If you don't change partition 2 to 07 (line 01D0) as well - You are essentially not allowing the system to find your NTFS drive volume with windows on it.


Nick Warren said...

Hi Abei,

Thanks a million for this. I was trying to create a Mirrored Dynamic Disk onto an SSD Drive. What a mission.

So, I broke the Mirror Set. Then did the '07' trick on the four partitions. Then deleted the two small partitions.

From there, the Acronis cloning software that came with the SSD was able to cope and close the HDD --> SSD.

Yours happens to be one of the few posts out there that fixes this issue.

Microsoft Win 7 backups of Dynamic Disks don't work as they require the same drive geometry on which to restore.



Nick Warren said...
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