While upgrading from Windows XP or Vista to Windows 7, you may face QuickBooks Printer not activated Error code 20 . This error happens because the ‘new operating system’ puts out the Hkey_ Current_config\ software key in the registry settings. In other words, the entries found on the key are not updated when you upgrade the Operating system. In some applications, the exact key is used to store the internal settings that lead them to fail the update. If you are a QuickBooks user and have upgraded to Windows 7, there is a good chance you can face this issue. This app uses ‘Hkey_current_config\software’ key to store the internal settings, and because the registry key is not updated there is a definite chance that the app will not work correctly.