I was getting the same error up to today; now PD4.0 works again with my BC partition.
Try this:
- disable the HD in Virtual Machine Configuration > Hardware > Hard Drive
- quit PD4
- now open PD4 and re-enable the HD in VMC (select the right HD and be sure to set it as a BootCamp HD)
- try to boot the VM and everything should work (for me worked like a charm and after Windows booted up I had to reinstall Parallels Desktop Tools because the installer started up automatically).
PS: I've Windows Vista Ultimate x64 SP1 on my BC partition.
Try this:
- disable the HD in Virtual Machine Configuration > Hardware > Hard Drive
- quit PD4
- now open PD4 and re-enable the HD in VMC (select the right HD and be sure to set it as a BootCamp HD)
- try to boot the VM and everything should work (for me worked like a charm and after Windows booted up I had to reinstall Parallels Desktop Tools because the installer started up automatically).
PS: I've Windows Vista Ultimate x64 SP1 on my BC partition.