I have burned the UBCD iso onto a cd using Nero Express (as instructed on this website). I have altered the BIOS settings so the old PC whose HD I am trying to wipe starts up from the CD. Indeed, the menu then appears fine but when I try choosing any option using the function keys, it quits (to DOS?) with a 'file not found' error. I have navigated around the CD using DOS trying to find one of the disk-wipe progs like Autoclave and DBAN but I have no idea how to run them once I find them! I have tried every command that 'list commands' suggests but I have no idea what the right way to do it is.

Please help. Pardon my basic ignorance.
Bertie