I recently got one of those dreaded NTLDR messages when I was attempting to open my virtual machine. I am running Win XP Pro on a MacBook 10.4, Accessing via Parallels 3.0. The virtual machine will not recognize the DVD drive so I could reboot, nor the USB drive. My local tech's only suggestion was to "start over" with my virtual machine, by uninstalling/reinstalling XP and Parallels. Any comments or suggestions would be appreciated.