At first, you need to know the precise reason for error 3371. It can occur because of a missing or corrupted file, which is otherwise needed to run QuickBooks. Also, damaged MSXML file, outdated Windows, and antivirus software plays a substantial role in causing QuickBooks error 3371. To fix it, you would like to update your Windows to the most recent version by following these steps – click Windows/Start icon on your computer, then select All Programs from the list and click on Windows Update. If the problem persists, then you'll need to re-install the QuickBooks program employing a clean install tool available from the QB website. Moreover, you'll also contact the QB experts to repair the error.