Quote: It will not boot unless the IDE controller almost matches the original. (i.e. earlier model SiS chipset to a new model SiS)
I've been booting up the same hard-drive for the past 6 years on probably 8 different PCs by now almost every one a different MoBo manufacturer; everything ranging from an old Cyrex chip, to T-Birds, to an Athlon64, without ever formatting the HD. And though it has progressed OS' over time, it was never because it needed to. It's been long retired as the primary drive, but it still boots up whenever needed without fail.