Guest: I wanted to try your code for implementing DirectShow filters using DMOs but found an unresolved reference to AtlSetPerUserRegistration. I cannot seem to find out anything about this ATL function.

It appeared in Visual Studio 2008, just comment it out.

Guest: I am still using VS 2005, but I figured that at least there should be some docs on it at MS. Found nothing. I will try commenting it out.

Yes, it is an undocumented [yet] feature but generated by default project wizard.

I am pretty sure Microsoft will document it soon and it will be quite useful: it will allow registration of COM classes from under non-admin account. However it might be still not useful enough for DMOs because they will need additional entries under HKEY_CLASSES_ROOT for which there will still be insufficient permissions.

See also: ATL and Visual Studio C++.NET 2008 Goodies