To fix Excel not responding or hanging issues, you can follow these troubleshooting steps: 1. Run Excel in safe mode to identify any add-ins, startup folders, or toolbar settings causing the problem. 2. Automate safe mode troubleshooting using the Microsoft Support and Recovery Assistant. 3. Install the latest updates for Office and your computer. 4. Check if Excel is being used by another process and wait for the current task to finish. 5. Investigate Excel file details and contents for any factors causing performance or crashing issues. 6. If the file is generated by a third party, test the features in new files outside the third-party application. 7. Perform a selective startup to identify conflicting applications and services. 8. Repair Office programs to automatically fix errors and resolve issues with Excel. 9. Check if antivirus software is up-to-date, as outdated software may cause performance issues.