Bogus bios hard drive failure warning

PC halted on boot claiming one 3TB drive and one 1TB, hitachi drives were iminently failing.
I use them for recorded TV files using WMC.
So I ran crystal disk info, and both drives smart data says they are GOOD, no problems.

My 1 TB WDC boot drive for win7 has a yellow caution, so will do another macrium backup.

So why do you suppose the bios flagged my two hitachi drives like that?
smart says those 2 have 73,000 power on hours, but no flag as bad, could it be my bios just assumes such a drive must be bad?

Power on is 8 years so the drives are old and will need replacement.
SMART data is not a particularly reliable indicator.

Test them as much as you like, but they are old and need replacing.

Your WD drive which is maybe 6 years old also is coming up for replacement.

Not good to use old drives, they are increasingly likely to fail.

well they can fail, let them. They simply hold TV recordings, which WMC is constantly recycling.
For my use, nothing is very important on any of the drives, but of course it is a pain to deal with reinstalling OS.
This PC has win7 ultimate and also win10 pro which can be dual booted, but I only use win 7 since it supports WMC, which is the entire purpose of this media PC, and watching other streaming video.

I had upgraded from 7 to win 10 pro, but hated it for this use as no WMC, so I reinstalled a win 7 I bought off ebay for $7

Other potential problem is the MB is also old, could die someday. IT is Aspen MSI 7548. I have thought about using an SSD for the boot drive, but then I would hate to buy one and have the board die, So best thing is wait till it does, then get a board that uses NVME ssd drives. That could still be years away.