You don't state the o/s so this is for windoze 98..
Start/settings/Control panel
Add new Hardware. Next, Next,
No. I want to select, next, next
goes through detection process.
At this point it may find lpt1. If it does follow the instructions
else
next - brings up a list of device types
scroll down to ports(Com & LPT) & highlight it
next
Select the one you want & follow the instructions.
For Win98 you should need the system cd to complete this.