How to solve the error code 0x800706ba: RPC server unavailable during Office 2021 installation

There are several steps you can take to solve the error code 0x800706ba during Office 2021 installation:

1. Restart your computer: Sometimes, a simple restart can fix the issue. Restart your computer and try installing Office 2021 again.
2. Check if the RPC service is running: Press the Windows key + R to open the Run dialog box. Type "services.msc" and press Enter. Look for the "Remote Procedure Call (RPC)" service and check if it is running. If it is not running, right-click on it and select "Start".
3. Check if the RPC service is set to automatic: In the same Services window, right-click on the "Remote Procedure Call (RPC)" service and select "Properties". Under the "General" tab, make sure the "Startup type" is set to "Automatic".
4. Check if the Windows Firewall is blocking the RPC service: Press the Windows key + R to open the Run dialog box. Type "firewall.cpl" and press Enter. Click on "Allow an app or feature through Windows Firewall" and make sure that "Remote Assistance" and "Remote Desktop" are allowed.
5. Disable third-party antivirus software: Sometimes, third-party antivirus software can interfere with the installation process. Disable your antivirus software temporarily and try installing Office 2021 again.
6. Run the Office installation troubleshooter: Microsoft provides a troubleshooter tool that can automatically fix common installation issues. Download and run the Office installation troubleshooter from the Microsoft website.