The description is nonsense.

This function has absolutely nothing to wethere the time is UTC or not.

When the input time is UTC the output time is also UTC.
When the input time is local time the output time is also localtime.

It depends if you called GetSystemTime() or GetLocalTime() before.
This funtion always converts 3 o'clock into 3 o'clock.
Its just another structure for the same time.

The timezone does not matter.

This function truncates towards zero, it does not round. This should be mentioned.

It'd be nice if the function documented whether the time returned is in UTC or local time. I can deduce that since FILETIME is in UTC this should return a UTC time, but it's possible the function does a conversion. I shouldn't have to test it to find out.

[DllImport("Kernel32.dll", SetLastError=true)]
private static extern long FileTimeToSystemTime(ref FILETIME FileTime, ref SYSTEMTIME SystemTime);

<DllImport("Kernel32.dll", SetLastError:=True)> _
Public Shared Function FileTimeToSystemTime(ByRef FileTime As FILETIME, ByRef SystemTime As SYSTEMTIME) As Long
End Function