Replace a new CMOS. but I had to face same problem

You need to change the battery (normally a CR-2032 - which is available everywhere).

Unplug the computer, remove the cover, and set it down with the motherboard facing up. Look in the corners for a battery holder and the battery (it may be under a PCI card - which you will have to remove before changing the battery). When you locate the battery, very carefully remove it and replace it with the new battery. Replace all parts (seating the boards correctly) and button up you computer. Re-install the cables and turn it on.

You just need to replace the button CMOS Battery CR2032.
Reboot. Press F2 and enter the correct date and time.

Power down PC. Open the PC tower. Look at the motherboard and find the CMOS battery. Looks like the picture below. Make sure you touch some sort of metal area on the PC to ground yourself before touching the components. Use something thin to pop the old CMOS battery out. The CMOS batteries are usually universal. CR2032 is the usual type used. These can be found at a CVS or Walgreens. Once you have acquired the next battery, make sure the CR2032 is facing up and just press it in.

-Ben P.

Are you sure you replaced the CMOS battery with a fresh one? Did you install it backwards (the plus side should be UP). I've only seen a bad CMOS battery cause that problem. I would try one you know is new and check the installation.

Good luck.

It looks like your CMOS battery is running out. Try to replace the new one, enter the CMOS setup and save.

http://cgi.ebay.com/GENUINE-ACER-250-REAL-TIME-CLOCK-RTC-CMOS-BATTERY-/250619795738?pt=Laptop_Batteries&hash=item3a5a1a991a

Method.

When your Gateway computer is switched off, it still keeps track of various system information such as the date and time, thanks to a small battery that never powers off. The size and thickness of a dime, the CMOS battery can run out and need to be replaced. You can swap out a dead CMOS battery with a new one by removing the Gateway computer's side access panel.

Difficulty: Moderate
Instructions Things You'll Need:

• Phillips-head screwdriver
  

• CMOS battery replacement
  

1. 1
   

   Shut down the computer. Remove the power cable from the back of the computer case. Disconnect the cables for the monitor, mouse, keyboard, and printer.
   

2. 2
   

   Set the computer case over on its side. Use the Phillips-head screwdriver to remove the two case screws at the far left end of the case.
   

3. 3
   

   Slide the side access panel to the left and remove it from the computer case. Find the CMOS battery port, which will be located to the lower left of the processor in most Gateway computer models.
   

4. 4
   

   Lift up the plastic clip holding the CMOS battery in place. Slide a fingernail under one side of the battery and lift it off the motherboard port.
   

5. 5
   

   Check the orientation of the new battery and compare it to the CMOS motherboard port. Push the new battery into place in the same direction that the old battery was facing. Push down the plastic clip.
   

6. 6
   

   Set the side access panel back onto the Gateway computer case and reattach the case screws. Plug in the Gateway computer and power it on.
   

when you power up the computer press F2 or "del" key then you enter in bios then set time and date settings then save setting.then check .
If you still face this problem you should need to change the cmos cell it is on motherbord becasue may be its voltage are down.so purchase new cmos cell and replaced it on mother bord.

some motherboards will switch on and run after removing the cmos battery also but in some motherboards it is not possible it depends on the manufacture design ...

try changing the cmos battery with the new one that cmos battery might have lost it s power ...

after that also if you face the same problem then there may be some dust particles accumulating in the processor fan due to that it might not be able start clean them and refit and try it ....

if you still face the same problem then if you are using UPS then remove the connection from that and give the direct connection this may solve your problem if there is some problem in the UPS battery ....

any doubts you can reply me
regards

-Dileep

On this ASUS motherboard just beside the Lithium Battery for CMOS an SMD transistor needs to replaced . Sorry I can't remember the component number as well as the legend numbersince I do not have that motherboard with me anymore , but mind you IF YOU DO NOT HAVE EXPERIENCE WORKING WITH SMD COMPONENTS DO NOT ATTEMPT TO REPLACE THE TRANSISTOR AS YOU MIGHT END UP DAMAGING NEIGHBOURING COMPONENTS AND DAMAGING THE MOBO BADLY.