Both values are stored in a version resource in the
project. Open the version resource and type away.
As far as the difference, FileVersion is mainly used
for tracking on specific file's version; ProductVersion
is useful for tracking files that work together and have
to be synchronized as a package. Like ODBC, ADO,
Office DLLs, etc.
This lets you change the version of XYZ_BASE.DLL
for a bug fix, and still know it's synchronized with
XYZ_ETN.DLL; they'll have different file versions,
but you can keep the product version synchronized.