After installation of SafeGuard Enterprise, the USB keyboard does not work within the Windows safe mode options screen on a HP DC7800p SFF machine.
Known to apply to the following Sophos product(s) and version(s)
SafeGuard Device Encryption 126.96.36.199
SafeGuard Device Encryption 188.8.131.52
Microsoft Windows Vista,
Microsoft Windows Seven
What To Do
To enable USB keyboard support within Windows safe mode menu, you will need to update the BIOS version of the computer to version 1.28A.
According to HP, the BIOS version 1.28A fixes an issue where the system stops responding (hangs) while Microsoft Windows is loading when keys are pressed and multiple keyboards are present.
The BIOS now checks USB UHCI controllers for ownership changes or halt state before attempting runtime device enumeration.