Posting for Google / History sake..

C:\ProWin20\32bit had a file that was very, very broken. 

• We couldn’t rename it
• We couldn’t change it to not read only
• We couldn’t drag it to desktop
• We couldn’t zip the entire 32 bit directory that contained it
• We couldn’t attach it to an email 

The whole time Microsoft just kept saying it was "corrupt and unreadable".  We don't know how it got in this state.  

Ultimately, we worked around this issue by renaming the C:\ProWin20\32bit directory & reinstalling

If you run into this problem during an update, try renaming, deleting, moving whatever file it's complaining about and then try again.  Then post here with details about what you did to rename/delete/move it, since I couldn't figure out how to do so with just the one corrupt file.