Re: Can't find Microsoft executables in Wine browse C:
In Wubi systems, your "C" drive is automatically mounted under /host.
But ... be careful ... modifying, deleting, or adding files to your "C" partition from inside Wine risks corrupting the Win7 filesystem -- and could render it unbootable.
Also, Powerpoint does not work well under Wine. It gets at best a Silver rating:
Ubuntu 17.04 Mate, Mint 18.1 Mate; MS Win 8.1, MS Win10 Pro.
Will not respond to PM requests for support -- use the forums.