How to Change the System/Boot Drive Letter in Windows 2000

ID: Q223188

The information in this article applies to:
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Datacenter Server
  • Microsoft Windows 2000 Professional
  • Microsoft Windows 2000 Server
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

This article describes how to change the system or boot drive letter in Windows 2000. For the most part, this is not recommended, especially if the drive letter is the same as when Windows 2000 was installed. The only time that you may want to do this is when the drive letters get changed without any user intervention. This may happen when you break a mirror volume or there is a drive configuration change. This should be a rare occurrence and you should change the drive letters back to match the initial installation.


MORE INFORMATION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

To change or swap drive letters on volumes that cannot otherwise be changed using the Disk Management snap-in, use the following steps.

NOTE: In these steps, drive D refers to the (wrong) drive letter assigned to a volume, and drive C refers to the (new) drive letter you want to change to, or to assign to the volume.

This procedure swaps drive letters for drives C and D. If you do not need to swap drive letters, simply name the \DosDevice\letter: value to any new drive letter not in use.

  1. Make a full system backup of the computer and system state.


  2. Log on as an Administrator.


  3. Start Regedt32.exe.


  4. Go to the HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices key.


  5. Click MountedDevices. On the Security menu, click Permissions. Check to make sure Administrators have full control. Change this back when you are finished with these steps.


  6. Quit Regedt32 and start Regedit.exe Go to the HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices key.


  7. Find the drive letter you want to change to (new). Look for "\DosDevices\C:".


  8. Right-click \DosDevices\C:, and then click Rename.


  9. Rename it to an unused drive letter "\DosDevices\Z:". (This will free up drive letter C: to be used later.)


  10. Find the drive letter you want changed. Look for "\DosDevices\D:".


  11. Right-click \DosDevices\D:, and then click Rename.


  12. Rename it to the appropriate (new) drive letter "\DosDevices\C:".


  13. Click the value for \DosDevices\Z:, click Rename, and name it back to "\DosDevices\D:".


  14. Quit Regedit and start Regedt32.


  15. Change the permissions back to the previous setting for Administrators (this should probably be Read Only).


  16. Restart the computer.


Additional query words: Mounted Devices partition

Keywords : kbenv
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbhowto


Last Reviewed: December 29, 1999
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