Every computer contains a complementary metal-oxide-semiconductor (CMOS) chip and battery. The chip stores BIOS information in its memory, and the battery allows the chip to retain this information when the computer is powered off. If the CMOS battery is removed while the computer is turned off and receiving no power, the CMOS chip's memory will be erased. The CMOS battery in a Levno Laptop is located just under the memory compartment cover on the back, which makes it easy to remove when you need to reset the CMOS memory.
Turn off the computer, unplug the power adapter and take out the main battery.
Unscrew the captive screw on the memory compartment cover and take the cover off.
Gently pry the battery out of its holder with your screwdriver, and disconnect the cable. Wait for at least 30 minutes, then put the battery back in.
Put the memory compartment cover back on and tighten the screw.
Put the main battery back in the laptop and turn on the machine. The CMOS is now reset.