Resolving Installation Error 0x80070643 for Office 2021

Follow these tailored steps to overcome the installation error 0x80070643 for Office 2021:

1. Reboot your computer and attempt the installation of Office 2021 once more.
2. Temporarily switch off your antivirus programme and proceed with the Office 2021 installation.
3. Ensure your Windows operating system is fully updated; if not, perform the necessary updates and install Office 2021.
4. Remove any older Office installations that may interfere with the new Office 2021 setup.
5. Utilise the Microsoft Office Installation Troubleshooter to identify and rectify any installation problems.