I have a PC with Windows 8.
In the last 2 days I have set the clock (the one which appears at the right bottom corner of the desktop) twice, as it paused on a certain hour and (Maybe the hour before I shutdown the PC?).
What can cause that?
Could the BIOS battery be at fault?
One can only presume what you might have meant by "clock is stopped", that every time you boot-up after shutting it down completely, the clock perhaps resets (and perhaps resets to 1-Jan-1970). However, while you work on the PC, over time, the clock keeps ticking. You could always manually set the time, but powering-off, you lose the set time.
Highly likely that the CMOS battery for the onboard Real-Time Clock (RTC), managed by the PC BIOS is dead. So indeed, changing the CMOS battery should be attempted first to fix this.
You could also stop the PC boot-up, and enter the PC BIOS, check the time reported there. If it shows 1-Jan-1970 in BIOS, and you set the date/time to current, and shutdown/power-off and reboot, then re-enter BIOS and again find time as 1-Jan-1970, then it is almost certainly the CMOS battery.
