Is there a chance the hard drive has another partition that may have
been set up by using BootCamp or some other utility? If you choose
to look into the Mac HD and see the named partitions already on it,
(some will appear as additional separate hard drives) a few will be
curious but essential with OS X Recovery, among other, set apart and
in their own named hard drive partition.
http://www.apple.com/support/bootcamp/
http://www.apple.com/support/osx/
There are some utilities that could help find out what is using the 10GB
missing from the hard disk drive. A few are in the OS X itself, others are
out there which may or may not be worth their trouble; esp if acquired
from questionable sources, due to threat of adware or malware content.
I'd wonder if you didn't have a second bootcamp partition, or other space
occupied by other software, given the Windows and VMware use in it.
If you have a suitable complete backup on external sources, you could try
a fully new installation, and then for OS X content migrate from backup.
That may be a bit extreme. Before you try to be rid of unknown partitions
be sure they are not part of the main OS X installation, as that could be
helpful to have later on should you need to reinstall original OS X or use
the recovery section specific to that computer. If not already erased.
Is the issue with space in the main HDD or in the external where you put W7?
Good luck & happy computing! 🙂
