Error 1625: This installation is forbidden by system policy occurs when installing
Possible Causes:
You're not logged in as an administrator.
Your Windows Installer system policy prevents you from installing digitally-signed software updates.
Possible Solutions:
Log on to your computer with administrative rights, and try reinstalling.
Log on as an administrator and retry installation, and retry.
If that doesn't work, you will need to enable installation of digitally-signed software updates:
Open a command prompt as administrator
From the command prompt, type gpedit.msc, and then click OK.
On the Local Group Policy window, navigate to Local Computer Policy, then Computer Configuration, then Administrative Templates, then Windows Components, and then Windows Installer.
Double-click Prohibit non-administrators from applying vendor-signed updates.
Click Disabled, and then click OK.
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