On Windows 7 systems that don't normally have a keyboard attached, it may not be possible to enter a PIN during boot time. This is due to the lack of supported input entry methods on a touch screen display prior to entering the Windows boot phase. With no physical keyboard available or an emulated physical keyboard (USB or otherwise) during boot; the PIN option cannot be supported by Windows.
There may be concerns over the lack of security when no PIN is used, however in this scenario BitLocker still provides acceptable security using the TPM only as long as there isn't additional access to the system available through DMA ports.
For information on PIN requirements and the volume master key please see this TechNet article:
http://technet.microsoft.com/en-us/library/cc162804.aspx
There may be concerns over the lack of security when no PIN is used, however in this scenario BitLocker still provides acceptable security using the TPM only as long as there isn't additional access to the system available through DMA ports.
For information on PIN requirements and the volume master key please see this TechNet article:
http://technet.microsoft.com/en-us/library/cc162804.aspx