I have 4 internal drives all of which used to show, one is SSD the boot drive the others HDD. One win10 and the second a backup of win10. These 2 work although booting from the back up is painstakingly slow. The 3rd one is win7 which booted up this morning OK. The last one is just for video storage. Now only 3 show in BIOS but in disk management or this computer there are only 2 showing, the win10 drives. OS is win10. If the win7 disk is the only one connected then it will boot win7.
Before the fault were you able to choose which OS you wanted to boot to? Double check your boot priority setup and that drives are in AHCI mode. Might be an idea in BIOS to reload setup defaults and then reconfigure from scratch. Regarding the video drive, does it spin or is there no power? Could be a faulty sata or power cable, sata port, or ultimately the drive may be dead - can you try it in another machine/put it in a docking station/external case to see if it works?
thanks, I seem to have fixed it but not sure how, a couple of new sata cables as I had some, swap the ports around now all showing and working OK. This may sound odd but the SSD did not seem to like sharing a channel with a HDD, either wouldn't be seen at all or took ages to boot. I gave it it's own channel and it fired up as it should. The power cable to the video drive was also what I would class as loose but it was spinning up. So I am unsure what initiated the problem but glad it was not the usual nightmare one gets with this sort of thing
