Restoring my MacBook to its original configuration
Restoring my MacBook to its original configuration
Yes, we need to perform a fresh installation of the operating system.
I don't understand why you can't delete a Mac. You weren't aware of that.
Activate recovery settings. Press +r to power on your Mac. Confirm you're on a PC for accurate instructions. Enter recovery mode, then choose reinstall osx. Make sure you have an internet connection and your Apple ID and password ready. Downloading and installing OS X may take several hours depending on your speed.
Also, which MacBook are you using? Does it feature an HDD or an SSD?