Antilles: I'm not saying Windows is more secure than Linux at all, my belief is the complete opposite. Unfortunately the workplace isn't necessarily a place where one is put their opinions into practice.
djs: We had a developer with his own laptop PC. I'm not site support, so it's not my business... but I agreed with IT, it pissed them off to no end. He left, and I'm sure he still has all the licensed software on it (screwing the company). There was no way to know how secure it was... and moreover, they wanted admin rights to it because if he was gonna use it as a company resource, they should be able to manage it as one when it was here. No go. Lots of issues arose from it besides being out a bunch of licenses. (He was a developer, stuff got expensive. He was also friends with a VP which is why he was allowed to bring it in anyway.)