TurboTax error 65535 happens when you try to install the software for the first time. To fix this error, you need to:
• Use the fix it tool by downloading it from TurboTax.
• Launch the task manager and disable unwanted services.
• On the run command box, check whether a service is running.
• Finally, you can try to install the update manually.
These steps will help you clear the error from TurboTax. However, if you face any kind of unwanted errors or issues you can contact TurboTax support number to avail services from professionals.