Sets the valid data length of the specified file
_WinAPI_SetFileValidData ( $hFile, $iLength )
|$hFile||A handle to the file. This file must have been opened with the $GENERIC_WRITE access right, and the
$SE_MANAGE_VOLUME_NAME privilege enabled. The file cannot be a network file, or be compressed,
sparse, or transacted.
|$iLength||The new valid data length. This parameter must be a positive value that is greater than the current
valid data length, but less than the current file size.
This function sets the logical end of a file. To set the size of a file, use the _WinAPI_SetEndOfFile()
function. The physical file size is also referred to as the end of the file.
Typically, the _WinAPI_SetFileValidData() function is used by system-level applications on their own private
data. Not all file systems use valid data length. Some file systems can track multiple valid data ranges.
In general, most applications will never need to call this function.
Search SetFileValidData in MSDN Library.