I have an HP Pavilion ZE5000 notebook. The internal clock was slow and I was told by HP support that the CMOS battery needed replacement. HP provided me with a part number and I purchased an equivalent at Radio Shack (CR2032, 3.0V). I went to a local laptop repair shop and when the technician opened the top of the laptop he was able to find a battery underneath the keyboard. However, the size of the battery found in my laptop was about 1/3 of the size smaller than the one I purchased at Radio Shack. The tech replaced the battery in my laptop with a new one (from his shop) and reset my clock. However, when I tried it at home, the problem was not solved; my clock is still slow. Any help is greatly appreciated.