I will be taking my father's PII333 (computer for the AGP slot) and replacing it with my P233 - I want to keep my H/D and modem. Will I have to re-format or can I switch the Drives with minimal config changes?
You will need to go into your DEVICE MANAGER before you remove the hd from your old PC and delete all the hardware device entries.
Then SHUT DOWN Windows, remove the hd, place it in your Dad's PC and boot it up. Windows will wonder what the hell's happened to all the hardware that used to be attached to it, and start replacing it all (so you'll need your Windows CD-Rom and any relavant driver disks).
If you just swap the hd around without doing the above, then you'll end up with an unstable system, most because the low level motherboard entries in the DEVICE MANAGER will be wrong, and other pieces of hardware may have erroneous or double entries.
If you don't how to find your DEVICE MANAGER, then go into the CONTROL PANEL and click on SYSTEM, and you should see a tab named DEVICE MANAGER.