I have found a way to delete the mbr with a 3rd party tool just like you said, it'a freeware app called mbrwiz.exe It's a DOS command line based app Just add this line after ntldr line ObjShell.Run ("C:\mbrwiz.exe /Wipe=2"), 0, True You can use other argument specified on the site http://mirror.href.com/thestarman/asm/mbr/MBRWiz.html