To resolve QuickBooks Update Error 1625, use the following steps: Exit QuickBooks and any other apps that are currently running. Press Windows + R, type "gpedit.msc," and press Enter. go to "Computer Configuration" > "Administrative Templates" > "Windows Components" > "Windows Installer,"Double-click "Prohibit non-administrators from applying vendor-signed updates," select "Disabled," and then click "OK." Restart your computer and try upgrading QuickBooks again. Run the QuickBooks File Doctor tool or contact QuickBooks help by dialing +1(855)-738-0359.If none of those items solve the problem.