Hardware (un)support for performance counter.

In the Win32 API there is a function QueryPerformanceCounter that queries the value of a very high-resolution performance timer. Its documentation states:

"If the installed hardware supports a high-resolution performance counter, the return value is nonzero.
If the installed hardware does not support a high-resolution performance counter, the return value is zero."

What kind of hardware would *not* support a "high-resolution performance counter"? On all the machines I have used this function on, there is never a problem. I don't know how this performance counter is implemented in the circuitry; I was just wondering if anybody has ever come across or is aware of a system that doesn't support this.

Thanks,
J.C.