I tried to restart while keep pressing Command-R However, my keyboard is not mac keyboard. There is windows-R. It works exactly like Command-R in all circumstances. Well, I keep failing to get into
How to restore my Mac in Recovery or Internet Recovery
Use Disk Utility to erase an Intel-based Mac - Apple Support
How to Factory Reset Your MacBook or iMac
media./wp-content/uploads/2016/02
How to reinstall macOS - Apple Support
How to Boot/Start Mac in Recovery Mode?
What to Do When You Accidentally Deleted Macintosh HD?
How to Factory Reset a Mac If You're Ready to Start Over
Accessing the macOS Recovery Environment
How to reset your Mac to factory settings