I've encountered a strange situation on 3 new Dell computers now that may be a part of this problem: each of the 3 computers, at some point between coming out of the box and being put on a client's desk have had their drives encrypted with Bitlocker. I personally handled these machines from unboxing to deployment, and at no point in time did I enable Bitlocker for the boot drive. And yet, each of the three machines have had their drives encrypted. I'm absolutely certain this has happened, as the third machine has been in my lab for testing all week. One of the first things I did was check for encryption when it first came in and the drive was NOT encrypted on Monday. This morning, when I went to check on it, the drive was encrypted. According to the Bitlocker-API Operational log, the first entry appeared at 5pm yesterday.
I don't know what is going on, but this is extremely unusual.