Instructions for "cleaning out" a printer install from a test PC:

Note: for Vista systems, one must first select "run as administrator" before changing properties or deleting anything. Regular access mode is OK for simple viewing or printing a test page.

Power off / detach printers and then delete the printer(s). Then right click on an empty space in the Printers & Faxes window to get to print server properties. In that window, use the drivers tab to see if any drivers are still present (often the case) which should then be delete. 

Optional, but suggested for the brave: Go to the widows\inf directory and starting with the highest numbered oemX.inf file and working toward the a low number such as oem3.inf, look at it in a text editor (just drop it on a shortcut to or copy of Word or other text editor) - if it is one of our printers then I delete the oemX.inf and equivalently numbered oemX.PFN file.
 
If the virtual serial TVS driver had previously been used, then check Device Manager's listing of Ports(COM &LPT) and delete any virtual com ports. Finally, optionally power cycle the PC - this allows Windows to release USB port numbers that are no longer connected to a driver so the system can start again with port USB001. When booting the test PC, check to see what USB ports are still hanging around using USBPortView, and again use it after an install to see what USB port was assigned to the printer.

When doing any re-installs it is important to refuse any offers by Windows to automatically search for a driver, instead point it to the xxxInstall directory that contains the printer files.

FYI: Windows "Print Test Page" will only print the first 6" when the paper selected is "short" (the install default is the long value) and will not operate the knife cut at the end of any job when that property is "NO" (the install default).

