Clock drift on Windows

Question

I\'ve developed a Windows service which tracks business events. It uses the Windows clock to timestamp events. However, the underlying clock can drift quite dramatically (e.

Answer 1

http://www.codinghorror.com/blog/2007/01/keeping-time-on-the-pc.html

PC clocks should typically be accurate to within a few seconds per day. If you're experiencing massive clock drift-- on the order of minutes per day-- the first thing to check is your source of AC power. I've personally observed systems with a UPS plugged into another UPS (this is a no-no, by the way) that gained minutes per day. Removing the unnecessary UPS from the chain fixed the time problem. I am no hardware engineer, but I'm guessing that some timing signal in the power is used by the real-time clock chip on the motherboard.