On my Macbook Air (Rev-C 2009) is encrypted the Bootcamp Windows 7 partition with Bitlocker. Since the MacBooks don't have a TPM installed, I used an external USB key to store the Bitlocker key. That USB key needs to be inserted during the Windows boot phase. This worked perfectly well on the MBA. See BL FAQ on MS Technet: http://technet.microsoft.com/en-us/library/ee449438(WS.10).aspx#BKMK_NoTPM The same setup unfortunately does not work with my new MBP 2011 15". The Bitlocker pre-installation test fails. It appears that this new MBP model does not properly read USB flash sticks during boot and therefore is not compatible with Bitlocker. I tried different sticks (FAT formatted) and it's all the same. Are there any parameters that can be set in the MBP boot rom to ensure that USB Flash is read during boot process? Any other persons who experienced the same?