The standard way of doing this on Windows machines is to make all time based functions (ie animation and physics) scale correctly over variable time slices and then use QueryPerformanceCounter() to determine how long it is since the function was last called. It can also be safely used for profiling function execution times as it tends to produce a much higher resolution than the other timing functions.

This function should be available on all fairly recent PCs (pretty much anything that you want to run a FPS on these days). There is another thread here somewhere on exactly what machines it runs on.

Regards,
Ralph Potter
ralph.potter@digital-magi.com, http://www.digital-magi.com