I have a legacy DOS program that prints to the LPT1 port. We have a program that maps the LPT1 to the attached USB Printer (Lexmark using the Universal Print Driver) using the DOS command 'Net use //printer lpt1 /persistent:Yes'. It works for the most part but we have ran it the problem of the computer randomly "dropping" the printer. Once this happens it is not showing up when I enter 'net use' in a dos command window. Any ideas as to why the printer is losing the mapping?