I'd like to 'borrow' the thread (good news, FbF) and ask the experts a question on the same topic:
Some may recall that I swapped out my IDE C drive for a SATA drive, and all was ok. Now, with increasing frequency, the BIOS is 'forgetting' the hard drive boot order, requiring access by me to 'remind' it. APART from a possible failing CMOS battery, is there anything else that can cause this?