I have been trying to figure out a way to prevent people from booting off of CDs, USB devices, etc. [For reasons which should be pretty obvious :D] The machine I am currently working with is a Dell Optiplex. I have gone into the BIOS, and disabled all items in the boot sequence, except for the SATA HDD, and set the administrator password [to prevent changes in Setup]. Even with this set, you can still tap F12, which brings up a list of devices, and choose which one to boot from. I inserted a linux live cd, and was able to boot from it with no problems.
Does anyone know of a way to prevent users from accessing the boot device listing? I have been searching around, but have not found anything yet. I will edit this post if I find the answer before anyone responds.
Thanks in advance.
The closest thing I have found so far, is to turn off the message that says 'Press F12 for boot device list'. Though if you already know which key to press, or mash enough keys, you can still get to it...