Thanks for the info, mjf. That link in particular was very helpful. Maybe part of my problem is that I'm running Windows 7 on an Apple Mac (which I configured for dual-booting using Apple's "Boot Camp" utility). Internally, Macs use a GPT partitioning scheme but Boot Camp effectively "fudges" a fake MBR scheme to present to Windows. In other words, Windows thinks that the underlying drive is MBR when in fact, it's GPT.
When I first copied my Win7 partition and used bcdedit
, both menu options were taking me to the same boot partition. This ties in with that article's comments about moving a partition to a new offset. I suspect that the copied partition originally had the same GUID. Therefore in both cases, my Windows 7 boot manager was simply jumping to the first offset it found for that particular GUID.
I've now changed the GUID of the copied partition and switched to EasyBCD instead of bcdedit. This time I get a little further, though not much.... I can still boot into my original Win7 partition but when I try to select the copied partition my boot fails with the error "autochk program not found - skipping AUTOCHECK" (at which point, the system resets itself). Interestingly, this isn't the error that I'd expect from reading that article if I had an offset problem ("winload.exe.....is missing or corrupt"). So I'm guessing that my GUIDs and offsets are now fine but I must have some other kind of problem.