https://qbenterprisesupport.com/quickbooks-error-code-20/

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.and also quickbooks pdf converter printer not activated

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 ‘Hkeycurrentconfig\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.

There are two ways to solve the error and go back to smooth functioning. Kindly note that to perform both the solutions you need ‘Administrator Access’ to the system, else the solutions will not work.

To create a ‘Registry Backup’.
Go to the ‘Registry Editor’
Click Computer
Press File>> Export >> Save it.
To create a ‘System Restore point’.
Manually create ‘System restore point for Windows 10’ with the below steps. The method works for Windows Vista, 7, 8, etc.

Click ‘Create’ button, and select ‘Local Disk C’ in the system protection
In the prompt window fill in ‘description’ of the restore point.
Type date of the restore point.
Click ‘create’ button to initiate the process
The process should be completed within a minute or so.