Can the Volume Shadow Copy service be used in Windows 7 by a non-administrator

Question

I'm trying to use the Volume Shadow Copy service on Windows 7, and have had a look at the MS vshadow code and AlphaVSS. These appear to provide enough detail to do what I need, but I can't make anything work unless in Administration mode - I get "0x80070005 - Access is denied" on the first real COM call after CoInitialize and CoInitializeSecurity if in normal user mode, even if the user is a member of Backup Operators.

An entry in the application event log suggests this is a COM issue:-

The COM Server with CLSID {0b5a2c52-3eb9-470a-96e2-6c6d4570e40f} and name VssSnapshotMgmt cannot be started. [0x80070005, Access is denied.]

but I can't find any such server as VssSnapshotMgmt so I've no idea how to change access to it for users. I also believe that it can be done, since Backup works on my machine without elevating priviliges.

The application is intended for dumb clients (in every sense) so I'm against using administration mode if at all possible.

Any clues on how to connect to this service?

Answer 1

The command-line tools/samples that Microsoft ships with VSS: vshadow.exe on older versions (upto Windows Server 2008) and diskshadow.exe on newer versions both require to be executed with Administrator privileges.

Though it is not explicitly mentioned that invoking the VSS COM APIs should have administrator privileges - considering the fact that Microsoft's own (supported) utilities have this restriction, it would be safe to assume that end-user applications that use the VSS COM APIs would require the same privileges.