Reinstalling macOS Big Sur typically takes about 30 minutes. To ensure a successful reinstallation, please follow the steps below:
1. Back up your data. Before you begin, make sure all of your data is backed up and stored in a safe place. This is especially important if you have any important documents, photos, or other files that you don't want to lose during the reinstallation process.
2. Download the macOS Big Sur installer. You can do this from the Mac App Store.
3. Restart your Mac and hold down the Command and R keys to enter recovery mode.
4. Select “Reinstall macOS” from the Utilities menu.
5. Follow the on-screen instructions to finish the installation process.
6. Once the installation is complete, you can restore your data from the backup you created.
If you have any questions or need additional help, please don't hesitate to reach out.