Q1. Can anyone provide a link that explains how computer clocks work
under Win NT/2000/XP)?

Q2. From an MSDN KnowledgeBase article:
"If the system time and the time maintained by the RTC drift apart by
more than one minute, then the system time is re-synchronised to the
RTC time"

If the RTC is not system time, then what function does it serve and
how does the system clock function?

Q3. Interrupt level 28 in the Windows microkernel is the clock
interrupt. What sets this interrupt? Is it the software clock?

Q4. Do different HAL drivers (e.g. HALX86 and HALMPS) implement time
differently? How?

Thanks in advance dor an help.