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Drive not mapping, already in use

I have a login script to map network drives for users. One user, who happens to be at a remote site with a site-site vpn, is having issues with the script. One of the drives is not mapping successfully. The other drives map correctly without issue. If I try to manually map the drive with command prompt Net Use command,  I get System Error 85, already in use. There are no drives physical or otherwise that I can see using the letter F. If I try to navigate to the path and right click and map, F is not presented in the drop down. It is really important that this mapped connection use the letter F

I tried command Net Use * /delete, which deleted all of the connections but did not specifically state F. Still unable to map to that letter manually.
3 Solutions
reg delete "hkcu\network\f" /f


reg delete "hkcu\network" /f

Then reboot and let the Logon Script remap them.....
Oh, and that's in a CMD prompt....
Either the local drive letter is used by a USB mass storage device or else it is remembered from a previous session. Run the following commands just once to fix the problem:
 net use * /del /yes
 net use /persistent:no

Also try:


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jlargerAuthor Commented:
johnb6767: 1st command returned with error that file did not exist. 2nd command complete succesfully. On reboot, did not successfully map the drive. Manually tried to map with same System Error 85.

mmaris: I agree something is holding F as a reservation for whatever reason. Ran both commands successfully. Did not fix issue. Link more or less rehashes what we have tried here, so no go there.

Other suggestions?
yo_beeDirector of Information TechnologyCommented:
if you goto computer management > disk manager> select HDD and select change drive letter to see if F is even available.  

Wondering if maybe theres a ghost somewhere, maybe under MountedDevices/MountPoints2 in the registry??

Awaiting last question though....
jlargerAuthor Commented:
Now I just feel silly. Could have sworn I had already checked this, actually I'm sure I did I just must have missed it. In opening Computer Management > Disk Manager I found F was assigned to an empty removable device (facepalm). Reassigned that drive letter and now all is well.

Is there any way to prevent Windows from assigning the F letter to devices in the future?
Jlarger, in the past I have had a few co-workers with similar requests regarding their home networks and they told me that a freeware utility called USB Drive Letter Manager worked well for them:


That being said, I prefer to keep my Windows builds rather lean to optimize both their stability and security, so if I can find a simple alternative to installing another application I normally take that route.  On our domains, we manage to avoid the type of scenario you encountered by ensuring that our log on script doesn't map any network drives within the first half of the alphabet.  Our earliest network drive is "M:" and that always seems to prevent any type of external device conflicts.
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