If you want proof, you could check the time options panel again.
Now that just seems easier to me.
Sync Your Clock With Internet Time Servers from the Vista Command Prompt
If you have an issue with your system clock losing time, you've probably had to go and re-sync your clock with the internet time servers. The problem is that there are just way too many clicks required to get to the right screen, so the command line is much simpler.
