Yesterday, I installed a GTX 760 onto my motherboard and then moved my hard drive cage underneath my 5 1/4 bays. Today, when I booted the computer up about 20 minutes ago, it just took me to the American Megatrends screen, which is the exact same screen that I saw when I first posted my computer when doing an external build. After rebooting again, it did it, but the third time it said "detected SATA device" and proceeded to boot up to windows. That's all it does now, is wait for the hard drive to be detected then it boots into win 8.1. Also the screen to go into BIOS hangs around for about 5 seconds where it was about a split second before. I disconnected by keyboard, still same problem. Any ideas?
It sounds like you plugged your boot drive into a different SATA port when moving the drive and your BIOS wasn't finding it in the usual place i.e. Seagate ST1000DM003 on SATA 0-1, or something like that. Just look in your BIOS to see where the boot drive is located and change the boot priorities to that drive.
What I did is after a bunch of reboots after not doing anything, the long screen with "press f2/ delete to enter bios" remains, but the american megatrends screen is gone. Now a flashing bar appears in the top left corner for about 3 seconds then boots me into win 8.1. So, I went into the BIOS settings and made my boot drive the boot priority, still same thing.