1. Open the command prompt on your computer by choosing the 'Start' and 'Run' menu options.
2. Enter the command, 'msiexec/unreg' in the 'Open' text field followed by the 'Enter' key. This will unregister the Windows Installer on your computer.

3. Re-register the Windows Installer by selecting the 'Start' and 'Run' menu options. Enter the 'msiexec/regserver' command in the 'Open' text field, then press the 'Enter' button.
4. Upgrade the Windows Installer application version on your computer if the previous steps did not eliminate the error. The updated application is available through the Microsoft resources download site listed in the resources below.
5. Verify the Windows Installer service is enabled on your machine. To do so, select the 'Start' and 'Run' menu options and enter 'services.msc' in the 'Open' text field followed by the 'Enter' button.
6. Double-click the 'Windows Installer' service, and if the field beside 'Startup Type:' is set to 'disabled,' change the setting to 'enabled' by selecting the value from the drop-down menu box next to the field.
7. Re-download the third-party application you are trying to install to ensure the download file is not corrupted.