On the other hand, a system is usually much perkier after a clean install.
How's your day so far?
ETA: EPIC WIN.
It took two very basic installs of XP SP2 (using a slipstream disk) and a little bit of three-hard-drive Monte in the registry, but I am apparently back to where I was on Wednesday, except my C: drive is now 500 GB rather than 160 and it's not making that annoying cricket noise. Haven't unattached the old drive yet; may not. But I'm not gonna use it for anything important. And DriveImage XML worked like a champ.
Hahhhhhhh. Muuuuuch better.