>>Drive mappings work on a per-user basis. The COM object probably runs as a System user so it will not see "your" drive mappings (from your personal profile). It's always better to provide the proper UNC path (\\MyServer\) instead of mapping to a drive.
>
>Thanks, this approach is much better.

Well not necessarily. Drive Mapping is much faster than UNC lookups because UNCs are looked up over and over again, so there's more overhead. This may or may not matter much...

If you're not logged on as Interactive the user's drive mappings won't show up, but you can use a couple of WinApi calls to set up your own drive mappings in the current session as part of the startup routine.