When I enable USB legacy support in my BIOS, it seems to work fine, as long as I don't have a particular external USB disk connected and powered up. If I do have that, the computer locks up during boot (during BIOS device discovery; Windows isn't in the picture yet).
I accept that either the BIOS has a bug or the external disk enclosure has a bug, and I doubt there is anything I can do about it, but I still have questions about how to avoid this in the future.
Is this likely to be a BIOS bug? Or an enclosure bug? How can I test without involving a second PC? (Hint: I don't care enough to use a bus analyzer. :-)
Assuming this is an enclosure bug, anybody have recommendations for how to shop for a replacement enclosure which gets this particular thing right?