Thanks for the suggestion. Looking at this again I didn't provide enough info. Just in case it wasn't clear: in both XP and 7 the drive is internal and connected to the SATA controller. It's not in a USB enclosure or anything like that.
Is it the FAT32 that 64bit may reject? I only did that because that drive used to be in a USB enclosure and it went back and forth between Mac and Windows. The 64bit thing seems more trouble than it's worth; 64bit XP came out what, 7 years ago I think, and still it can be impossible to find certain 64bit device drivers
, even for newer devices. I wonder how many 64bit applications are really out there.
The 7 box is here with me in Ohio but my XP box is back in California, so I can't stick the drive back in to convert it under XP. I've got a boot CD with a boatload of utilities on it, I think I'll use that and see if there isn't a partition manager that'll do the conversion.