Perhaps you are looking for this -> BIOS Settings Glossary (DX48BT2)
Moreover, as you were saying that you need information about almost everything in the BIOS, well just in case you don't find information on everything here, you might want to search Intel website and do a bit of googlingas we all do and you will get details on every single thing. You might also want to give Wikipedia a try looking for a quick information on any of the technical terms. For support on your motherboard, go to Support on DX48BT2.
As for Marvel RAID and wanting to know if you have a RAID online, you can access RAID BIOS Console on the start up of your computer by pressing Ctrl+G and looking into it for a possible RAID configuration however I won't advise that for you, rather another easier way but let me tell you first that RAID can not be built on a system with a single HDD. For a minimum RAID configuration, you require at least 2 HDDs on your system. Furthermore, if you have 2 HDDs and someone else installed OS for you, you can still also confirm it by accessing the disk manager from your OS and looking at the capacity of your 2 hard drives and the available drive to you and the OS. In case you have installed the OS yourself, you'd very well know that you never really built a RAID at the first place.
And as for the message being displayed on pre-boot, it's not effecting your computer or doing any harm .. rather just displaying information because either you have a RAID card installed on your system or because of the motherboard having RAID configuration capability. You can overlook that without having to worry lest its effecting your day-to-day operations.
Hope this helps, however if you feel you want further assistance, feel free to contact us.
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