1. Mount the PVS 7.15 LTSR CU4 iso
2. Open the iso mounted and go to folder: Console > ISSetupPrerequisites.
3. You will see a list of Powershell snap-ins. Click on each of them and install one by one
4. Now go to folder: Server > ISSetupPrerequisites.
5. You will again see a list of Powershell snap-ins. Click and install the following:- –Broker_PowershellSnapin_x64
6. Go to Programs and features and check: The snap-ins will be upgraded to CU4