Hardware or computer failure hopefully only comes around every five to ten years.
It is easier if you have another computer nearby to test the hardware first, then if the hardware is functioning OK, the working computers printer card or mother board could be suspect.
Check connections and cable first, then hardware and computer.
For the parallel port software:
Check the settings for this port and make sure is set to 0378 in the resources section of the properties. Change the I/O range to 0378 by changing the basic configuration in the properties of your LPT1 port.
For Win XP Goto Start/Control Panel/System/Hardware/Device Manager/
Then click on ports(com and Lpt), Right click for the properties of your Printer port(lpt1).
In the resources section, it should be set for
0378-037F for Lpt1.
If not, unclick - use automatic settings and then change the basic configuration so that the I/O range is 0378-037F. This should suit Lpt1.
The software only sends commands via the LPT1(378) port, unless adding 2 extra ports with the Timer software. This port has to be a parallel printer port for this to work.
The commands are sent along the actual pins 2-9, so then the relay cards can plug directly into the port.