Check the BIOS battery
The BIOS battery is on the motherboard and is essential for permanent memory power the PROM (BIOS).
If the battery is low the BIOS, the computer might not be included, or included but with the default settings. Constantly loses date and time.
Check the battery BIOS:
1. Turn off the computer.
2. Disconnect the power cable running to the back of the system unit.
3. Unscrew the screws holding the side cover of the system unit.
4. Remove the side cover.
5. Put the system unit on its side.
6. Find the location of BIOS battery on the motherboard:
7. Screwdriver tilt mount batteriesfor the battery jumped from the nest:
8. Pull out the battery.
9. Measure with a voltmeter the battery voltage. To do this, flip the battery. Then one probe of the voltmeter lean to the side of the battery and the other to the surface. Normal battery voltage — 3 Volts:
If You are on the computer constantly resets the date and time, then most likely You have the battery BIOS.