Computer Has Lost Sense of Time

I don't know why, but recently my computer can't keep track of time anymore. A little bit a go, I was almost late for work because my computer said I had about an hour before I had to be there, but in fact I only had about 20 minutes (this was when I was working at McDonald's). I reset the clock. I have then been having to reset it more frequently as the last couple of weeks have been going on. I have Windows set to automatically update the clock, but it only happens once a week. My friend Neil says I can change that setting, but he never explained how. So, I have downloaded a freeware app called Time Synchronizer. It updates to an atomic clock at the frequency that you set. I have to have it update every hour because I have now figured out I am losing about 2 seconds every minute. Might not sound like too much, but that is two minutes every hour. Leave the computer for 10 hours and come back, the computer is 20 minutes off. Windows' little weekly update isn't very effective for this problem. I would like to find out what is causing this because right now I haven't really solved the problem, I am only masking it. So, for now my clock should be okay, but now that means I need yet another app eating up my precious RAM. If anyone has any idea's what's causing this, feel free to comment. I've already checked to see if there was some kind of IRQ conflict with the real-time clock, but that doesn't seem to be the issue.