Thanks - I'll try using the 2nd option to see if I can detect the mapped drive issue.

You really can't win at this, can you? If you can't see the drive, you can't get the UNC for it. If you don't have the UNC, you can't map it.

Side question: What is the downside of running an installer as 'highestAvailable' or even 'asInvoker'? Just curious.

Thanks again for your prompt help, SB is the best!

Tom