Destroying hard drive seems a little expensive.
Try this:
You will need two USB drives
Disconnect all the internal drives
create one live Ubuntu/Tails or any other linux USB
on 2nd USB create encrypted container*
transfer bitcoin wallet address generator to 2nd USB and run it from Live USB
create Bitcoin addresses and save them on 2nd USB
(optional but highly recommended) encrypt your private keys with strong password.
**important** create many back up copies
*cross platform encrypted container is hard to find since TrueCrypt (the only cross platform container that I know of) is no longer in development.
Edit:
as an added layer of security, use a spare computer that will never go online to generate Bitcoin addresses