If you don't feel comfortable opening the computer case or can't locate the CMOS reset jumper, you can use a USB flash drive to reset the BIOS password. Here's how:
Remove the screw on the back of the case and slide the cover off. lenovo thinkcentre m720q bios password reset
The password prompt should no longer appear, allowing you to configure new security settings. Alternative: CMOS Battery Method If you don't feel comfortable opening the computer
The Lenovo ThinkCentre M720q has a CMOS reset jumper on the motherboard that can be used to reset the BIOS password. Here's how: lenovo thinkcentre m720q bios password reset