Hard disk with key icon or symbol

[nevare00]

I have a Lenovo T400. When I go to "my computer " or windows explorer a Key icon appears over the hard drive. I want to know what does it means?. It is an encryption hard disk? .

That is because when i boot the laptop with a linux distribition like backtrack it does'nt detect the main hrd drive. Thank's

nevare00

[emtee3511]

I found this: http://forums.anandtech.com/showthread.php?t=132902