HP Print Driver Crash when printing to networked printers

I ran into an issue recently where any application would crash when printing to a network printer. Our environment is unique in that we are printing to a Windows print server (using Guest privileges), but users on the network are logging in using the Novell client.

The crash would not happen with generic Microsoft drivers that came with Windows XP, but it would happen with any HP-branded drivers. Our first workaround was just to use PCL or PostScript drivers that closely matched the printer, and hope for the best.

In the end, we found out that when printing with the HP drivers, it would write to a file in the Windows directory called hpmnwun.ini. The contents it would write were:


[NWUSERNAME]
NOVELL=1
NWUSERNAME=testuser

Fixing the issue was a two step process:

1: Erase the contents of the file
2: Change the NTFS Permissions of the file to make it read-only by all users (even Administrators)

I think this forces the HP drivers to print to the printer in the standard Windows printer sharing way. When the HP drivers detect the Novell client installed, it writes the NWUSERNAME info to the file and must try to print in an ‘NDPS friendly’ way, which causes the application to crash when printing to a standard Windows shared printer and not a NDPS printer.