Error 91: "Disk Manager has been detected on drive %lu" when imaging or modifying a partition

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Error 91: "Disk Manager has been detected on drive %lu" when imaging or modifying a partition

Situation:
When using a Symantec partitioning or drive-imaging program, you see the message "Error 91: Disk Manager has been detected on drive %lu."

Solution:
If you no longer need to use Disk Manager on your hard drive, you can fix Error 91 by removing the Disk Manager signature from the Master Boot Record (MBR). If you are not sure whether you still need to use Disk Manager, contact your hard drive manufacturer. They can tell you not only if you still need Disk Manager, but also how to repair it.

Note: If the Disk Manager signature is on a drive other than the primary master, you must change the drive's jumpers to make the drive the primary master. This is necessary because WRPROG can back up only the first head of the primary master drive.

If you determine it is OK to erase the Disk Manager signature, perform the following procedure:

To erase the Disk Manager signature

Create a DOS boot diskette.
You can create a DOS boot diskette by choosing the option to "copy system files" when you format a floppy diskette under Windows 98.
Copy the FDISK utility to the boot diskette.
The Fdisk.exe file exists in the \Windows\Command directory on any computer that is running Windows 98.
Copy the Wrprog.exe utility to the boot diskette.
You can download Wrprog.zip from the Symantec FTP site. After you download the file, unzip it and copy the unzipped file to the boot diskette.
With the boot diskette inserted in the floppy drive, boot your computer.
Run Wrprog.exe to make a backup of the data that is contained in the hard disk's first head.
To create the backup, type the following command at the command prompt:

wrprog /bak head0.dat
Run FDISK with the CMBR switch to clean out the Disk Manager signature from head 0 of the primary master drive. To do so, type the following:

fdisk /cmbr 1

where the number 1 signifies the primary master drive.
Reboot the computer

The error should no longer occur.

Technical Information:

Notes:
This error is reported if Disk Manager is detected in the first head (head 0) of the hard disk but is not running.
The reason for backing up head 0 is to provide a way to restore its data if you later discover that you still need Disk Manager. For information on restoring the backup file to head 0, read the document How to use WRPROG.exe.
The Head0.dat file is written by default to the location from which you launched WRPROG (in this case, the boot diskette). You can edit or restore this file later, if necessary.

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Document ID: 2004011466697262
Last Modified: 08/06/2004
Date Created: 04/13/2004
Operating System(s): All Supported
Product(s): DeployCenter Library 2.0, Drive Image 2002, Drive Image 7.0, Drive Image Pro 4.0, DriveCopy 4.0, PartitionMagic 7.0, PartitionMagic 8.0, PartitionMagic Pro 7.0, PowerDeploy Suite 2.0, ServerMagic for Netware 6.5, VolumeManager 2.0