Thank you for this question.
Well, the main reasons have been given by my friend Cpt/Dogfruit.
Assuming that it is an Intel (R) Desktop Board, here are my answers:
- Update processor support
- Update memory support for new speed
- Fix known issues.
- Update ME firmware
- Update RAID Oprom firmware
- Update Vbios
- Update Graphics Oprom
- Update the MEBx version
- Update PXE Oprom firmware
- Add/|Remove new features and settings like vt, emt64, tpm etc. in the bios due to known errata.
A very easy way to get an answer/s to this simple question is to download and read the latest Bios Release Notes for the Board. Once you have verified all the latest fixes, you then need to ask yourself the questions whether or not the board needs a bios update based on the problem that you are encountering.
Have a quick look at a release for an old 3 series intel (r) desktop board:
All the best,