It was an ominous error message – No valid disk drive belonging to the disk group was found (C1000086).
A colleague of mine had ran into some trouble with a computer system. Windows XP was constantly rebooting without showing a desktop and all attempts at recovering the operating system drive proved uneventful. The operating system drive had failed and I had replaced the drive without incident.
Data loss was not a concern. The computer system had a second hard drive and all files had been previously copied to the second hard drive. However, after accessing Disk Administrator the second hard drive was marked as a Foreign Volume and had not successfully mounted when the freshly installed Windows XP booted.
No biggie. Import the foreign volume and the disk would become available once again. That’s when the message appeared – Internal Error: No valid disk drive belonging to the disk group was found (C1000086) and an Event ID 2 was logged in the System Event Log.
The simple “Import Foreign Volume” option was not so simple. The hard drive containing the data was a dynamic disk and would not import. There was an option to convert the dynamic volume to a basic volume, but the message in Windows XP indicating that “All data would be lost” was telling me this was not an option!
In digging around and searching for a solution, I found some references to a utility that is included on the Windows XP SP2 Support Tools – dskprobe.exe. This would allow me to convert a dynamic disk to a basic disk without losing data if the disk in question was not using any of the new dynamic disk features such as using RAID or extended partitions.
After downloading the Windows XP SP2 Support Tools, I ran the installation. Make sure you choose Complete Install otherwise dskprobe.exe is not installed as part of the typical installation. Then, To convert a dynamic disk back to a basic disk without data loss follow the procedure outlined below:
- Run the dskprobe.exe program;
- From the menu, select Drives from the menu and then Physical Drive;
- From the list of drives that are shown, click on the Physical Drive that you want to convert to a basic drive. If there are two drives in the system, Physical Drive 0 will be the boot drive, and Physical Drive 1 will be the drive that is currently a dynamic disk and so on;
- Click Set Active to accept the drive chosen as the one that will be converted;
- From the Sectors menu, select Read and accept the defaults (Begin Sector 0, Read Sector 1) and click Read from the open dialogue box. dskprobe.exe will now display the chosen sector in hexadecimal;
- Scroll down through the values until you find 01C0 on the left hand column, and if you look at the third value from the left you will see the hex number 42;
- Change the 42 to a 07;
- From the Sectors menu, select Write and confirm all the dialogue boxes;
- Exit from dskprobe.exe and reboot the computer system;
- The computer system should detect new hardware and the drive that was once a dynamic disk is now converted to a basic disk, with all data intact.
It is recommended that a chkdsk be started on the newly converted drive to correct any errors that may be detected on the drive.
After running through this process, I was able to access and recover all my colleague’s data without any data loss. In fact, the drive is still in the computer system and functioning normally without any problems.
Some things to note when using this solution if there are multiple partitions on the dynamic disk, you can convert partitions as well by making changes to 01D0, 01E0 and 01F0 (Partion 2, 3 and 4).
Prior to making any changes to the actual drive it may be a good idea to create a Ghost image (or equivalent) of the drive. Thus if the drive becomes corrupt because of this attempt to convert the dynamic disk to a basic disk, the image can restored to the drive (or a similar drive) without any data loss.
While the error message No valid disk drive belonging to the disk group was found (C1000086) may seem intimidating especially if there is data on the drive in question, I have successfully used this process to recover several drives.
I am not responsible for any data loss that may occur using this method. This is a procedure that should be used only if you are sure of what you are doing and realize that there is a potential to complete destroy all data on the drive, leaving little or no chance of recovery. I cannot be held responsible for any damage caused by using this method.