HP Designjet 430/450C/455CA Series Printers - Error Writing to LPT1 Due to an Unknown System Error Message when Trying to Print
An error message is received when printing using the 4xx series Windows printer driver: Error writing to LPT1 due to an unknown system error.
Disable the bidirectional communication in the driver.
Choose Start, Settings, Printers to get to the printer dialog box.
Right mouse click on the icon for the HP Designjet 400 series printer, and choose Properties.
Choose the Details tab, and choose the Spool Settings button.
From spool settings click Disable bidirectional Support for this Printer.
Click Apply, then Ok.
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