Question My BIOS stopped booting my SSD on motherboard MSI B75MA-P45 !!

[ELdred]

Hi. Something very odd is happening and I am lost, I just spent 3 hours on this and nothing helped. So since a year I have a PC with motherboard MSI B75MA-P45 with newest BIOS (I updated it) and I normally work on Samsung 870 EVO 500 GB SSD (which contains Windows 10 with Vera Crypt). This evening I put 2 other SSD in my PC by plugging them using SATA cables (one completely new disk and second disk used one, bootable with Macrium Reflect for my backups). My usual Samsung 870 EVO didn't boot, so I unplugged both 2 other disks, but it didn't help and to this moment I still see "Reboot and select proper boot device" message when computer starts (even though it IS listed in BIOS with it's name) ! I tried switching SATA cables, changing boot order, changing different settings in BIOS, resetting BIOS settings to defaults from BIOS, then I reset CMOS battery, then I even plugged the damn disk using external USB case - no luck, I still get the "Reboot and select proper boot device" message! To make sure that the disk itself is not corrupted, I connected it in my laptop and it works normally, I can see Vera Crypt asking for password. WHAT IS GOING ON with this stupid motherboard in my PC? Please HELP

 

[CountMike]

Hi. Something very odd is happening and I am lost, I just spent 3 hours on this and nothing helped. So since a year I have a PC with motherboard MSI B75MA-P45 with newest BIOS (I updated it) and I normally work on Samsung 870 EVO 500 GB SSD (which contains Windows 10 with Vera Crypt). This evening I put 2 other SSD in my PC by plugging them using SATA cables (one completely new disk and second disk used one, bootable with Macrium Reflect for my backups). My usual Samsung 870 EVO didn't boot, so I unplugged both 2 other disks, but it didn't help and to this moment I still see "Reboot and select proper boot device" message when computer starts (even though it IS listed in BIOS with it's name) ! I tried switching SATA cables, changing boot order, changing different settings in BIOS, resetting BIOS settings to defaults from BIOS, then I reset CMOS battery, then I even plugged the damn disk using external USB case - no luck, I still get the "Reboot and select proper boot device" message! To make sure that the disk itself is not corrupted, I connected it in my laptop and it works normally, I can see Vera Crypt asking for password. WHAT IS GOING ON with this stupid motherboard in my PC? Please HELP

I don't think it's "this stupid motherboard" fault but a system corruption in the BOOT SSD caused by other bootable disk.
Did you make Rescue disk/USB with Macrium Reflect ? It has an option to fix BOOT problems if you BOOT from it.