If you encounter the message "QuickBooks not opening," downloading and installing the QuickBooks Tools Hub will be a wise option. QuickBooks should be closed. The QuickBooks Tool Hub's most current version must be downloaded. Save the file someplace you'll be able to locate it quickly. Launch the downloaded file (QuickBooksToolHub.exe). Install by following the on-screen instructions and agreeing to the terms and conditions. When the installation is complete, press the tool hub button on your Windows desktop to launch it.