I'm running Windows 2000 + SP4 + NTFS which I have just freshly installed AGAIN and now, the time will change itself intermittently by however much it feels it wants to! It's never 1hr or 2hrs, its usually 1hr 36mins, or 2hrs 12mins etc and it will go backwards or forwards.
I've never seen this problem all the time i've been doing IT and I hope someone else has! I've tried using a time sync program but even after setting it to check every 10mins, it still changes.
Hope someone can help!