C# – Cannot access files on drive mapped network share from a Windows service

cmapped-drivenetwork-sharewindows-services

I have a network shared folder mapped to a drive letter, which is accessible from Windows Explorer, from the command prompt as well as from my WinForms application without problem. It is also accessible from my Windows service using a UNC path.

However, when I attempt to access this network location using a mapped drive letter from the Windows service, access fails. The Windows service is configured to use my personal "Log On" account credentials, which is the same in all the above cases. I am an administrator.

Many customer sites utilize drive letters for network shares and I cannot always control this and force them to specify UNC paths instead. I need to be able to access network shares using drive letters from a Windows service.

What do I need to do to set up my Windows service, so that it can access network shared folders that are mapped to drive letters? My Windows service is written in C#.

Best Answer

Sorry; you can't access mapped drives from Windows services. As Sheng suggested, you can use a UI process to get the UNC path from a mapped drive and then pass this to the service, which must use the UNC path.

Related Solutions

Windows – Map a network drive to be used by a service

Use this at your own risk. (I have tested it on XP and Server 2008 x64 R2)

For this hack you will need SysinternalsSuite by Mark Russinovich:

Step one: Open an elevated cmd.exe prompt (Run as administrator)

Step two: Elevate again to root using PSExec.exe: Navigate to the folder containing SysinternalsSuite and execute the following command psexec -i -s cmd.exe you are now inside of a prompt that is nt authority\system and you can prove this by typing whoami. The -i is needed because drive mappings need to interact with the user

Step Three: Create the persistent mapped drive as the SYSTEM account with the following command net use z: \\servername\sharedfolder /persistent:yes

It's that easy!

WARNING: You can only remove this mapping the same way you created it, from the SYSTEM account. If you need to remove it, follow steps 1 and 2 but change the command on step 3 to net use z: /delete.

NOTE: The newly created mapped drive will now appear for ALL users of this system but they will see it displayed as "Disconnected Network Drive (Z:)". Do not let the name fool you. It may claim to be disconnected but it will work for everyone. That's how you can tell this hack is not supported by M$.

Windows – How to uninstall a Windows service if the files do not exist anymore

You have at least three options. I have presented them in order of usage preference.

Method 1 - You can use the SC tool (Sc.exe) included in the Resource Kit. (included with Windows 7/8)

Open a Command Prompt and enter

sc delete <service-name>

Tool help snippet follows:

DESCRIPTION:
        SC is a command line program used for communicating with the
        NT Service Controller and services.

delete----------Deletes a service (from the registry).

Method 2 - use delserv

Download and use delserv command line utility. This is a legacy tool developed for Windows 2000. In current Window XP boxes this was superseded by sc described in method 1.

Method 3 - manually delete registry entries (Note that this backfires in Windows 7/8)

Windows services are registered under the following registry key.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services

Search for the sub-key with the service name under referred key and delete it. (and you might need to restart to remove completely the service from the Services list)

Best Answer

Related Solutions

Windows – Map a network drive to be used by a service

Windows – How to uninstall a Windows service if the files do not exist anymore

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