Drive Letters Not Showing in Disk Management or Diskpart

Summary of problem – drive letters show in My Computer but do not appear in Windows Disk Management or with Diskpart command.  Causing problems with external drives.

Dell Dimension 8250 running XP SP2 with bios A04.

PC has internal floppy disk drive and two internal hard disks:

Disk 0 has a Dell boot (EISA) basic partition and an NTFS basic partition

Disk 1 is a second hard disk with a single NTFS basic partition.

In addition there’s an Iomega USB hard disk and I attach and remove various USB pen drives and other USB hard disk drives.  The Epson Stylus R300 printer also a USB socket and card readers.

The PC originally had an Iomega zip drive (B) but this was removed when the second hard disk was installed.

In My Computer the drives are shown as:

A:  Floppy disk

C:  Disk 0 basic partition

D:  Disk 1 basic partition

E:  DVD ROM drive

F:  DVD read/write drive

G:  EISA boot partition (Dell installed?)

H:  Gets taken by removable USB hard disks

I:  Iomega USB hard disk

L:  Epson Stylus R300

All seem to work OK with the ability to copy files etc (though I’ve left the EISA partition alone).

However if I open Windows Disk Management or use the Diskpart command they do not show drive letters for the drives C: D: G: or I:  But if I want to add a drive letter to a drive then C, D, G and I are not available.

I recently wanted to use CMS’s BounceBack Pro to create a full system disk that was bootable on an external USB drive.  This fails as it doesn’t recognise the external disk and CMS technical support says this is because drive letters are not properly assigned to existing disks.

Some time back I tried to connect a Netgear Storage Central with a HD that I could access over my wireless network.  The setup utility constantly failed with a message that it couldn’t assign a drive letter.  With Netgear support I eventually set it up using my laptop and they concluded the problem was again with the desktop’s drive letter assignment.

I’ve read all I can find on assigning drive letters but cannot find anything about how to somehow re-connect the drives to their existing letters.  As this is becoming a problem I need to get it sorted.

I’ve no idea when this problem started.  It may have been like it from the start as it was only with Netgear’s guidance I started looking at Windows Disk Management.