Problem:

Receive the following error message

An error was detected while installing c:\\windows\\MFUnweb.exe

The installer will attempt to undo any changes it has made to your system.

Resolution:

When looking at the log produced by the websync install in the temp directory it was discovered that the customer was attempting to run the the wrappack from a network drive when the directory containing the wrappack started with a $. The WebSync technology doesn't allow $ in network locations.  Placing the WrapPack in a standard location on their network and not a hidden one or copying it locally will resolve the problem.