How to delete info from a connected device on mac even system information? I connected today my Book studio for the 1st time and my mac crashed when creating a backup with Time machine. 

As a consequence I would like to delete the info that this external hard drive ever connected to the Mac. For instance, I see it in Time Machine preferences as a backup destination.

I can see that I connect My WD Book studio in the system information under hardware /firewire/firewire800/Book 1

Is there a way to do that? System information gave you the info about the device but not any way to edit it, or in my case delete it.

Thanks for your help. Problem resolved.
By any chance do you mean delete everything on the MyBook Studio drive?

If so open Disk Utility, select the drive in the left-hand pane and then click the "Erase" tab, select the format you want (best bet: Mac OS Extended (Journaled)) and click erase.

Everything (and I mean everything) on that drive will vanish in a cloud of unseen bytes.