Retrieves the number of milliseconds that have elapsed since the system was started
_WinAPI_GetTickCount ( )
The time will wrap around to zero if the system is run continuously for 49.7 days. You should check for an
overflow condition when comparing times. To obtain the time elapsed since the computer was started, retrieve the
System Up Time counter in the performance data in the registry key HKEY_PERFORMANCE_DATA.
Search GetTickCount in MSDN Library.