This is usually caused when you delete an existing partition or create a new partition on a hard drive in a previously unpartitioned space. As a result, Windows may reassign some drive letters when either of these functions are done.

To preserve existing drive lettering, delete and re-create the appropriate partition, and then restart Windows 2000 or Windows XP Setup (reinstall Windows). You can also delete and re-create a new partition outside of the Setup process, by using another operating system, by using the Windows 2000 or Windows XP Recovery Console tool, or by using a boot disk that contains partitioning software.