Put motherboard in its default settings
It's easy just take the CMOS battery out for 15 mins that should clear all the BIOS settings and therefore set it to factory settings.
Put motherboard in its default settings
I think what you want to know is how to reset the motherboard’s CMOS back to its default configuration. Doing this on the motherboard, all your previous configurations on the CMOS will be removed and will be restored back to its default setting. And this includes the password you applied on the CMOS, if you saved one to protect the configuration.
There are different methods that can be used on resetting the CMOS. When I was still a student before, one of the students created a program and we use it to clear the CMOS password. This is the easiest way of clearing the CMOS password. The other method is by removing the CMOS battery from the motherboard for a couple of minutes; let’s say 5 to 10 minutes or maybe longer.
The other way is by short-circuiting the CMOS battery while it is connected on the motherboard. This will indeed clear the CMOS but will eventually drain and make the battery weaker. You can also reset the CMOS by applying the right jumper settings found on the motherboard.