Restarting your Mac: Things to know about reinstalling your operating system

It can be quite useful to reinstall your iMac. If it no longer runs as fast as usual, such a fresh start is worthwhile. Even with major system updates, you should think twice before continuing to use the old version or the new update.

Restarting iMac: How to prepare for reinstallation

As with any Mac, you should do some preparation before you reinstall your iMac. First, create a backup of your data using Time Machines. Besides that, it is worth creating an additional backup on an external hard drive.

1. To reset the iMac to factory settings, you now need to delete your startup volume. To do this, restart the iMac and meanwhile press the "cmd" + "R" keys to launch macOS Utilities.
2. To erase the entire hard drive, navigate to "Disk Utility" > "Continue", select your startup volume and erase it.
3. Then select "Format" and then "MacOS Extended" before proceeding to erase the user.
4. Close the macOS utility and click "MacOS Reinstall" to reinstall the iMac.

update iMac to the latest macOS version

Alternatively, the iMac can also be updated to the latest macOS version High Sierra right away. Before doing so, check if your model is compatible with the latest operating system. This procedure will also speed up your iMac, as potentially faulty software will be reloaded all around. You can download High Sierra from the App Store. Then launch the "DiskMaker X" application and insert a USB stick with at least 8 GB of storage space. After that, follow the instructions of "DiskMaker X".