I am using a brand new Dell Latitude E6520. The notebook has double BIOS configurability with "Legacy" or "UEFI" mode. I have performed a first setup using UEFI, however the sound card is missing in the device manager list, without any "unknown device" appearing, as if the adapter is not visible to the system (hardware conflict under UEFI?) At this point I have performed a new setup using BIOS "Legacy" mode, and the sound card is fully functional. Performed then a third attempt, again in UEFI mode: no sound card "visible". I'm wondering if this is a BIOS/Firmware bug or if Windows 7 (64) may be fooled by the UEFI setup in some manner. What do you think?