I tried those process to fix it. But remain unchanged:
1. On the "Start" menu, click "Run.
2. In the "Open" box, type "msiexec /unreg", and then press ENTER.
3. On the "Start" menu, click "Run".
4. In the "Open" box, type "msiexec /regserver", and then press ENTER.
Also I have tried method 2, also remain unchanged;
Check permissions within the Installer folder. To do this, follow these steps.
1. Click on Start and in the Start Search bar > type in > c: /windows/installer.
2. Right click on c: /windows/installer at the top under programs and click properties.
3. Click on the security tab > Verify if System and Administrator account has Full access permissions.
4. The Everyone account should have read and execute permissions, List Folder Contents, and Read.
What can I do now for fix that problem?
Original title: Internal Error of 2503 & 2502