This error occurs when updating TurboTax.

If you're using Windows 10, try this

1. Right-click on the taskbar and select Task manager.
2. Look for Intuit update service in the process tab and end process.
3. Look for MSIexec.exe in the Details tab and end process.
4. Try installing Turbotax again.

If you're using Windows 7 or later, try one of these

1. Run the Windows System File Checker, then try updating again.
2. Re-register Windows Installer.
   1. Select Start > Run > and type MSIEXEC /UNREGISTER.
   2. Select OK (it'll look like nothing happened).
   3. Repeat steps 1 and 2, but this time type MSIEXEC /REGSERVER.
   4. Try updating again.
3. Start the Windows Installer Service.
   1. Select Start > type Services.msc in the search box and press the Enter key.
   2. Scroll down and select Windows Installer.
   3. Select Manual as the Startup type.
   4. Select Start, then OK.
   5. Try updating again.