Why is my clock slow in Windows 10?

[WPCentral Question]

why my clock is slow in windows 10

after I switched from windows 8 to 10 my clock is slower,missing about 10 seconds per minute

 

[realwarder]

re:

How old is the PC? The clock details are stored in the CMOS chip on board the motherboard. All that Windows does is display the time stored in the CMOS and, if necessary update it via the internet. A clock that starts running slowly, especially in a PC that is 3 or more years old, can usually be attributed to a failing CMOS battery. This isn't a big worry as if it is a battery you just replace it - well you or a PC technician depending upon how proficient you are at replacing internal parts of a PC.