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External Hard Drive loses drive letter

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Last Modified: 2012-05-10
I am using Win 7 and have an external Hard Drive for backup connected through the USB port. I assign a drive letter but when I reboot I have to go back in disk management and reassign the drive letter

Shouldn't it boot up with that drive letter?
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Commented:
Windows should assign the next available letter to the external drive since it is a removable disk.
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Commented:
I would like that but it did not

When I first attached it I had to go to disk management and assign the drive letter

When I reboot and look at My Computer it does not show

When I go to disk manager I see it but it has no drive letter

I re-assign and it works fine

??

Commented:
Have you seen my secon d post about USBDLM?

Commented:
Take a look at this key in the registry to see what letters have been assigned to what devices: HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

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Commented:
The attached shows the My Computer Hard Drives

The drives M and N (both mapped to same physical drive are the ones that disappear when I reboot

The registry entries are in the word document as well

What are all the ?? entries

I do have a SATA docking slot that I rotate backup drives through

THank you for looking at this
Hard-Drives.doc
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Commented:
Make sure you don't have automount disabled using the diskpart command:http://technet.microsoft.com/en-us/library/cc766465(WS.10).aspx

Commented:
If you can tolerate having your drives reassigned letters by windows, you can delete all the entries in HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices.

There should be one volume guid assigned per device:http://msdn.microsoft.com/en-us/library/aa365248%28VS.85%29.aspx.

Adding and deleteing drives causes this area of the registry to become disorganized with obsolete entries making it more difficult to assign letter values to drives in sequence.  By deleting all the entries and rebooting, the drives are assigned new letters in sequence making it much more manageable.

If this is a problem, you may be able to arrange the letters as they were through disk management.
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