Finally found the answer!
Thanks for all your effort!

Here is the solution for anyone interested:

Replace this line,
Code:
strComputer = "."
...with this code:
Code:
Set objWshNet = CreateObject("WScript.Network")
strComputer = objWshNet.ComputerName
The comment I got about it is, strComputer="." isn't always supported using the WinNT provider under Win2003...
Kinda strange but the replacement makes it work!

Thanks again!