Hi I've a Dell pc with a small, hidden diagnostic FAT16 EISA partition, before the Windows partition, on the system drive. Starting a few days ago, this formerly hidden partition appears to have become visible to Windows XP which automatically assigns it a drive letter. I used the command "mountvol /d" to remove such newly created drive letter, but it reappears everytime Windows boots or restarts, even in Safe Mode. Has anyone experienced anything similar? Is it possible that a certain registry setting relating to the (formerly) hidden partition has somehow been altered? If so, how can this be reversed so that no drive letter is assigned automatically to the (formerly) hidden partition? An interesting observation is that, in HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices, there is no \DosDevices\{x} (where {x} is the drive letter) which corresponds to the drive letter now assigned to the (formerly) hidden partition. I cannot use the Disk Management MMC Snap-in to remove the drive letter assignment, since selecting the partition and right-clicking only brings up a single "Help" line in the context menu, without any of the usual options (like "Change Drive Letter and Paths..."). By way of background, my current system drive was made by cloning the original system drive over a year ago. The latter is now used as an internal second drive. After the cloning exercise, the Dell hidden FAT16 diagnostic partition on the second drive (the previous system drive) was set to type 16 using PTEDIT32, whilst that for the current system drive remains as DE. Until recently, both these FAT16 partitions have stayed hidden to Windows XP and, for example, do not appear as drives/partitions when the disk defragmentator is used (although they can be viewed in "Disk Management", without any assigned drive letter). Checking with PTEDIT32 shows the DE and 16 type settings for the two partitions remain unchanged. Thanks in advance for any suggestions and feedback! Luke