all computers have had their administrator account name changed, administrator accounts have been locked down with strong passwords, and full administrative rights have been disabled on normal users (work group managers and LAN administrators have full rights still of course).

But still we find this kind of adware on computers where the user has browsed the wrong places and clicked the wrong ads. To make things worse, some of these can only be removed by logging into that administrator account even though the user couldn't have been signed into that account.

Tell me that's anywhere near as secure as a Unix box.