uhm i didn't mention the program because i use pc certify and it isn't cheap, nearly $500 but i need this for the work i do. it is currently on sale but still too expensive i would think for an occaisional user
run a search on the techimo i remember someone posting a link to a zero fill utility in the last few weeks (based on linux if i remember correctly, i tried it on a couple of drives and it worked fine)
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pccertify