I have the opposite problem compared to the author of this question:

Hard drive access denied from Windows Explorer (but works from command prompt as Admin)

I can see all the drive letters for a particular server in Windows Explorer, and can navigate through them exactly as would be expected. The drive letters are displayed in Explorer in parens to the right of the path info --

finalpathportion (\\server\otherpathportions) (driveletter:)

e.g.

jmerrill (\\server\users) (H:)

But the drive letters are not usable in a "Run as Administrator" command prompt. They have worked in the past, but I have since rebooted. I thought that perhaps I had to start a new command prompt having visited them in Explorer -- but that did not help. "net use" in the command prompt shows

Unavailable  H:        \\server\users\jmerrill   Microsoft Windows Network

with similar info for the other drives. I can do

net use h: /d
net use h: \\server\users\jmerrill

for each drive, and get the letters to be available in the command prompt. It is perhaps obvious that I don't think that it should be necessary to do that.

Does anyone have any ideas?