Strictly an outside possibility this is a Windows 2000 Fix I've had to use a couple of times when installing an Epson printer.
No Local Ports Are Available For Printers
Next time you boot up, have a look in the Event Viewer for error messages that might indicate the problem.
Start>Settings>Control Panel>Administrative Tools>Event Viewer
While you're in Administrative Tools, have a look at:
Computer Management>Device Manager
Notice there are no ports there even though they are shown in the Printer Setup dialogues.
This'll give you a flavour for the topic of IRQ Steering although, as the article says, it isn't a troubleshooter. You'll have to look further for that.
IRQ Steering
Notice you are advised to
disable Plug 'n Play in the BIOS for Windows XP. This is a possible cause of disharmony between Windows 98 and XP in a dual boot system on the same machine.