If you delete a partition during Setup, create a new partition using the new unpartitioned space, and then install Windows 2000 in the new partition, Setup may change some of the drive letters on the computer.
For example, assume you have a computer with one hard disk and two partitions, drive C and drive D, and a CD-ROM drive E. If you then delete the drive D partition during the Windows 2000 installation, create a new partition using the new unpartitioned spaced, and install Windows 2000 in the new partition, when Setup is finished you may find that Windows 2000 was installed on drive E and the CD-ROM drive has become drive D.
This problem can occur if you boot from the Windows 2000 CD-ROM or from the four boot floppy disks. When a partition is removed that holds a drive (logical or physical), Windows 2000 reassigns those remaining drives lettered after the deleted partition, and assigns the next available drive letter to the new partition.
To preserve drive lettering, delete and re-create the appropriate partition, and then restart Windows 2000 Setup. 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 Recovery Console tool, or by using a boot disk that contains partitioning software.
The drive letter of the drive that was deleted is assigned to the next available drive and the rest of the drive letters are moved up. This includes removable media.
If the hard disks in the computer do not have any defined volumes, a removable media drive may be assigned as drive C, and the CD-ROM drive then becomes drive D. A CD-ROM drive does not become drive C even if it is the only defined drive in the computer.