If you have the Boot Camp partition preprocessing failed VMWare Fusion error (which results in a resource busy) and have not solved it after reading all the VMWare forum posts there is a small chance this could help.
After I dropped my MacBook on the concrete floor I had to buy a new one. Restoring was easy since I had a recent SuperDuper! image.
However I never made a backup of my Windows 7 Bootcamp partition. Sometimes I ran that Bootcamp partition in VMWare.
So I decided to reinstall Windows 7 with the Boot Camp Assistant. After trying to import the Bootcamp partition in VMWare, I got the infamous Boot Camp partition preprocessing failed error.
Googling I found some possible solutions:
Unmounting Bootcamp partition or
None one of those solutions helped. I tried installing Windows 7 32 bit, Windows 7 64 bit. This did not help either. I blame Apple for their usability in this case. My mistake was as follows:
When running the Bootcamp Assistant you will be asked to create a partition. After restarting in Windows installation mode you need to select a partition where to install Windows 7. When you select the partition that Bootcamp Assistant made for you it will say that that partition can not be used. So I deleted that partition and created a new one. Wrong!! Not wrong for Bootcamp or Windows, since that will work flawlessly, but wrong for VMWare because it won’t understand it.
Don’t delete and create a new one. Just format it! Doing that solved the VMWare preprocessing error.
KnobsLeversButtons 
craaaaaaaaaap! this might mean i get to re-install Windows 7! Argh!
thanks for posting in any case!
THANK YOU!!! I have been working on this issue for weeks. The first question VMWare asks should be “did you use the partition that the boot camp wizard prepared?”