Recently a friend got an IBM Thinkpad 600E laptop. On boot up he would get an error 00161 and 00163 and would freeze. On researching the error code I found that this had to to with the CMOS battery being dead. I located a battery from batteries.com. They have an excellent battery search so you can get the correct one for your application . The battery I needed was part no. CR2025-WR. Ok now that I received it it's time to change the battery.
1. Turn off the notebook and unplug it. Also I took out the battery pack on the bottom.
2. The CMOS battery is located in the same panel as the memory cards. In this case the panel is located under the CD drive. You'll need a small phillips screwdriver to undo the panel.
3. Once you've removed the panel the battery is located close to the front of the notebook under a tab and you'll see the battery tucked underneath with a black and red wire plugged the board. Unplug the wires from the board. Then press down on the tab where the battery is and pull out the old one.
4. Connect up the new battery and plug it back in and replace the panel in reverse order.