HP 940c printer

I am trying to hook 2 computers to 1 printer. First coumputer is parrell 2nd is on usb. 2nd computer prints fine. First computer has error that reads: There was an errorwriting to LPT1 Port : for printer hp deskjet 940c. A printer timeout occured toincrease the timeout settings for your printer open printer folder click the icon for your printer click file menu and then click Properties. To continue printing click retry. windows will automatically retry after 5 seconds. I have done this but the same error come up. Is ther any help you can give me. John Gilligan