I want to make an x86 and x64 program to write all 0's to the entire hard disk. I have vb6 code but this won't compile to x64 so I was thinking of using AutoIt. Does anyone know if this is possible please? I have little experience of AutoIT. in Vb6 I use these APIs: Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As Long, lpBuffer As Any, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, ByVal lpOverlapped As Long) As Long Private Declare Function WriteFile