Are there you are encountering during this process?
: You likely pointed the update installer to the wrong folder, or your base game was not exactly on version 1.476.99.0 . FH4.Update.1.476.99.0.to.1.476.400.0.rar
Look for an executable application file (usually named Setup.exe or Update.exe ). Are there you are encountering during this process
the executable and select "Run as administrator" . FH4.Update.1.476.99.0.to.1.476.400.0.rar