I do hardware/software support and sometimes I need to zero out hd's because of sensitive data is on their before they re re used or recycled, I want to create something in VB that can do that, but I am not quite sure wher eto start, I have various cable+adaptors, USB2IDE/SCSI, etc, I want to be able to use it like that, any ideas where to start

Zeroing Out HDD's
Puca
.NET doesn't provide this functionality as it does not interact with low level code directly, you would have to use something like Assembly or C/C++ for this. Perhaps there exists some SDK some where that you can use within VB.NET but other than that there isnt much of a chance.
Generally there is an option for HDD's to zero them out using their own diagnostic tools.