Problem:

Customer moved from WIN 2000 to XP and even though he has LOG ON AS for the server set to a specific user with network authority he gets a X172 when trying to create a XDB location on the network drive.

Resolution:

If you are using the XDB Service - and not the blue screen, you have to go to Amin - services and in the Log On tab change from Local system account to a real network account that can access the network drive.  Once this is done you need to stop and restart the server and then you should be able to create the location.

The rest of this isn't us, it's XP.  http://support.microsoft.com/default.aspx?scid=kb;en-us;180362

This article describes the differences with mapped drive letters and UNC names on XP and Win2K.  Looks like you must use the UNC name instead of the mapped drive letter when running on XP or 2003. You still must use specific login on account tab in the XDB Service.

If I try to create a location in N:\\scrap\\robinc\\ntwrk I get the X172 error.  If I change the Path in the Create Location window (both location and forward log path) to \\\\mars\\users\\scrap\\robinc\\ntwrk, the location is created successfully.

Just so you know, this will really degrade performance.  Let me know if this works for you.