It complained again about "Invalid BIOS ID" but I ignored that since I have a dual BIOS motherboard -- yay Gigabyte. So I still have revision 1.6 tucked away in case revision F9 doesn't turn out well. But changing the parallel port settings to ECP+EPP removed the Windows complaint.
So I should be ready now to install the bigger HDD I got for my birthday. I "just" have to find the time :P (and then the time to install all the old programs... I can imagine getting the Internet to work again might be challenging as well since I don't remember what all I had to do last time to get it to work).