Why cmd.exe cannot access a lettter-mapped drive when it's “Run as…”

Question

Problem

I have Windows XP SP3 here in VMWare, quite fresh installation, with just a bunch of applications (Browsers, Office) installed.

When I:

1. Log in as a local Administrator
2. Using Explorer's GUI I connect a remote server as X:
3. Launch "Command prompt" via Start menu link by either:
   a) launching the link manually
   b) right-clicking the link, choosing "Run as..." and filling credentials of the same user

the former case works just fine, but in the latter one, cmd.exe cannot access X::

C:\Documents and Settings\Administrator>net use
New connections will be remembered.


Status       Local     Remote                    Network

-------------------------------------------------------------------------------
Unavailable  X:        \\server\share\folder      Microsoft Windows Network
The command completed successfully.

C:\Documents and Settings\Administrator>x:
The system cannot find the drive specified.

C:\Documents and Settings\Administrator>dir x:\
The system cannot find the path specified.

C:\Documents and Settings\Administrator>

Pre-analysis

I have compared various properties I could find about the processes (I'm not sure that all of them are relevant): environment, open handles, open DLLs, "Security" tab in Process Explorer and all of them are the same.

One thing I found is that when watching the attempt with Process Monitor, the succeeding one does four more steps:

"Time of Day","Process Name","PID","Operation","Path","Result","Detail"
"10:55:33.4784227 AM","cmd.exe","2792","RegOpenKey","HKCU","SUCCESS","Desired Access: Maximum Allowed"
"10:55:33.4785212 AM","cmd.exe","2792","RegOpenKey","HKCU\Software\Policies\Microsoft\Control Panel\Desktop","NAME NOT FOUND","Desired Access: Read"
"10:55:33.4785569 AM","cmd.exe","2792","RegOpenKey","HKCU\Control Panel\Desktop","SUCCESS","Desired Access: Read"
"10:55:33.4786210 AM","cmd.exe","2792","RegQueryValue","HKCU\Control Panel\Desktop\MultiUILanguageId","NAME NOT FOUND","Length: 256"
"10:55:33.4786650 AM","cmd.exe","2792","RegCloseKey","HKCU\Control Panel\Desktop","SUCCESS",""
"10:55:33.4787131 AM","cmd.exe","2792","RegCloseKey","HKCU","SUCCESS",""
"10:55:33.4912359 AM","cmd.exe","2792","CreateFile","X:","SUCCESS","Desired Access: Read Data/List Directory, Synchronize, Disposition: Open, Options: Directory, Synchronous IO Non-Alert, Attributes: n/a, ShareMode: Read, Write, AllocationSize: n/a, OpenResult: Opened"
"10:55:33.4924104 AM","cmd.exe","2792","QueryNameInformationFile","X:","SUCCESS","Name: \server\share\folder"
"10:55:33.4924860 AM","cmd.exe","2792","QueryInformationVolume","X:","SUCCESS","VolumeCreationTime: 9/6/2005 2:05:04 PM, VolumeSerialNumber: 109F-0912, SupportsObjects: True, VolumeLabel: DATA"
"10:55:33.4932539 AM","cmd.exe","2792","CloseFile","X:","SUCCESS",""
"10:55:33.4937810 AM","cmd.exe","2792","RegOpenKey","HKCU","SUCCESS","Desired Access: Maximum Allowed"
"10:55:33.4939097 AM","cmd.exe","2792","RegOpenKey","HKCU\Software\Policies\Microsoft\Control Panel\Desktop","NAME NOT FOUND","Desired Access: Read"
"10:55:33.4939451 AM","cmd.exe","2792","RegOpenKey","HKCU\Control Panel\Desktop","SUCCESS","Desired Access: Read"
"10:55:33.4940098 AM","cmd.exe","2792","RegQueryValue","HKCU\Control Panel\Desktop\MultiUILanguageId","NAME NOT FOUND","Length: 256"
"10:55:33.4940548 AM","cmd.exe","2792","RegCloseKey","HKCU\Control Panel\Desktop","SUCCESS",""
"10:55:33.4941023 AM","cmd.exe","2792","RegCloseKey","HKCU","SUCCESS",""

The steps CreateFile, Query* and, CloseFile are missing log of the failing one.

Question

What can cause such a discrepancy? Is this a bug?

Answer 1

Starting with Windows XP, each LSA logon session (not related to Terminal Services sessions) has its own set of drive letter assignments. If you use Run As... – whether the account is same or different – the function still creates a separate logon session with the credentials given.

More:

• Microsoft corporation (2011-06-24). Programs may be unable to access some network locations after you turn on User Account Control in Windows Vista or in Windows 7. ID 937624. Microsoft KnowledgeBase.

Answer 2

Because mapped drives are on a !PER USER! basis, the other user (which you do the RUN AS as) can not see it!

To win, you need to try mapping a drive in a batch which is being run as the user first.