TurboTax is one of the most popular tax preparation software programs today. If you have an account on TurboTax and encounter the turbotax error 5209 error code 907, you can follow the below-mentioned troubleshooting steps to get rid of the issue: 1. On your computer, close all the running applications. 2. Run the Windows System File Checker. 3. Register the WIndows installer again. 4. Press the “Windows+R” keys together to open the Run dialog box. 5. Type “MSIEXEC/UNREGISTER” and press Enter. 6. Click on “OK” and wait for the process to complete. 7. Restart your computer and check if the error code 5209 is resolved.