I am having this exact problem. Tried what you suggested about editing the file, but it just keeps running the 'upgrade' process, getting no further than step one before telling me that I need to perform a manual upgrade and being unable to access the disk properly.
Windows tells me:
Windows could not start because of a computer disk hardware configuration problem.
Could not read from the selected boot disk. Check boot path and disk hardware.
Please check the Windows documentation about hardware disk configuration and your hardware reference manuals for additional information.
Last edited: Nov 11, 2008