You can change the System or Boot drive letter in Windows 2000 by editing the registry.
I would only do this if the drive letter automatically changed, as when you break a mirror or change drive configurations.
First, I would try doing it in the Disk Management snap-in.
To accomplish the change:
01. Take a full backup, including the System State.
02. Logon with Administrative priveledges.
03. Use Regedt32 to navigate to HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
04. Select the MountedDevices key and use the Security / Permissions menu to make sure that the Administrators group has Full Control.
05. Exit Regedt32 and start Regedit.
06. Identify the drive or drives that need changing by looking at the \DosDevices\
07. You may have to rename, for example, \DosDevices\C:, to \DosDevices\Z: to free up the C: for a subsequent rename. You rename a Value Name by right clicking it and selecting Rename.
08. When all the drive letters are correct, exit Regedit.
09. If you changed permissions in step 4, use Regedt32 to reset the permissions.
10. Restart the computer.