If your Mac is on and responding, click the Apple menu and select Restart. If your Mac is not responding, press and hold the Power button to turn it off, then press the Power button again to turn it on.

Press F4 for regular Safe Mode. Press F5 for Safe Mode with Networking. Press F6 for Safe Mode with Command Prompt.

Safe Mode - This will open the standard safe mode on the Windows desktop. Safe Mode with Networking - This will open the regular safe mode with networking hardware enabled so that you can connect to the network and the internet. Safe Mode with Command Prompt - This opens the Command Prompt instead of the Windows desktop.