According to; http://en.wikipedia.org/wiki/BitLocker_Drive_Encryption it says Bitlocker is "providing encryption for entire volumes". However I just phoned Sony tech support and they tell me it is like EFS and encrypts file by file. I think Sony are wrong. Can someone reassure me that Bitlocker does indeed create an encrypted drive so it does not show the file names unless you have the encryption key? EFS obviously shows the filenames but not the file contents if you do not have the encryption key.