>I don't know why the print spooler must be turned off. Don't confuse the print spooler with the printer driver. I use the print spooler with an HP LaserJet printer and use ??? to send PCL commands to the printer without the windows printer driver hosing the codes.

David, I need to control PCU customer display, computer works like
cash register. I use generic printer driver for this purpose.
After each keystroke, display needs to be updated.
Print spooler causes a remarkable delay after keystroke and before
print output, making its usage impossible.