Actually, there's a relatively simple way for Win9x fam...
Before uninstalling the old system and installing the new system, copy your Win9x install CD (just the Setup dir, not the rest) to your local hard drive, in case you don't get CD-ROM.
Boot into safe mode.
R-Click on the "My computer" icon, select Properties.
Select "Device Manager" tab.
You'll see somewhere down there an icon titled either "Plug and Play BIOS" or "ACPI BIOS" depending on the type of PC you have.
Select it, then click the "Remove" button.
Shut down your computer, install the new hardware, and reboot.
The machine will ask for new drivers, and reboot about six million times, but EVERYTHING will be reinstalled - and I have never run into a non hardware-related problem when I do this.
And I did it ~300-400 times when I was a hardware tech. Worked great.
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche