To do that you are either going to have to hook the clock tick interrupt or mess around with the PIT. For information on PIT programming check out www.peroxide.dk. For information on hooking the clock tick interrupt, check out the RBIL.
NOTE: If the RBIL says do not hook the original timer interrupt then don't do it. If you do and forget to call the previous handler from your handler, your system time will be messed up. There is another interrupt that is also triggered every tick of the clock. This one is the one you should hook as it will not affect your system time.
