Why does the clock on Windows XP loose time?

Question

If you set the clock to what should be right, over time it will slow down and have to be reset. What caused this and how can it be fixed?

Answer 1

Internal clock on PC is not perfect. Over period of time it always would be off one way or another. What you should do is to configure clock synchronization.
Login as admin and double click the time field or open Date/Time dialog from Control Panel.
You will see "Internet Clock" tab.
Select it and check box "Automatically synchronize with time server"
Select one of the servers in the list. You also can sync to another computer on your network, if you have one.
Of cause, you have to be connected to internet from time to time for sync to work.

Answer 2

The clock in your computer keeps time by pacing itself against the computer processor speed; which is only so accurate. Therefore, over time it either loses or gains time. It is possible to connect to an atomic clock. For example, look up New York atomic clock in your browser, and you will find a free program that can update your computer clock with an atomic clock, when connected to the internet. A handy program, because it can also be used to tell the time at any place in the world

Answer 3

From my experience, the clock gets slow when your computer's resources are completely used up and your system clock "ticks" slower. When programs hang alot of system resources are used to clear the hang.