Plesk for Windows upgrade fails: The installation of the package 'plesk-repair-module' failed with code 1603

Symptoms

• The Plesk upgrade process fails:

PLESK_ERROR:  The installation of the package 'plesk-repair-module' failed with code 1603. (upgrade: Upgrading Plesk repair module...)

• Error within

  C:\ProgramData\Plesk\Installer\autoinstaller3.log

CONFIG_TEXT:  MSI (04): Info 1603.The file C:\Program Files (x86)\IIS\Plesk Repair Module\jsoncpp.dll is being held in use by the following process: Name: w3wp, Id: 66764, Window Title: '(not determined yet)'. Close that application and retry. 

Cause

DLL file is locked by IIS.

Resolution