The following example sets the last-write time for a file to the current system time using the SetFileTime function.
// SetFileToCurrentTime - sets last write time to current system time
// Return value - TRUE if successful, FALSE otherwise
// hFile - must be a valid file handle
BOOL SetFileToCurrentTime(HANDLE hFile)
{
FILETIME ft;
SYSTEMTIME st;
BOOL f;
GetSystemTime(&st); // gets current time
SystemTimeToFileTime(&st, &ft); // converts to file time format
f = SetFileTime(hf, // sets last-write time for file
(LPFILETIME) NULL, (LPFILETIME) NULL, &ft);
return f;
}