Guys,
Long story short, I had to rebuild my P67A-UD3 system after the P67A-UD3-B3 motherboard that was supposed to replace it got damaged. I had broken down the PC into it's bits before I discovered the damage on the new mobo. Doh!
I've rebuilt the system on the original P67A-UD3 mobo, exactly as it was before, but it won't boot. It has an intel SSD and Samsung HDD. BIOS sees the SSD, where the OS is, but apparently parts of the OS or required drivers are on the HDD because it fails with "DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER" after POST.
BIOS isn't seeing the HDD, even though it's all cabled up and connected. I| can't remember which SATA cable was connected to which port on the motherboard - is this likely to be the problem?
I noted down all the BIOS settings and they are the same as they were before. Somehow (I think there's a recovery option) BIOS went back to version F3. I've got it to F4 via Q-Flash so that it recognises my 2600K, but that's as far as it'll go.
Any thoughts?