If you didn't change anything in the BIOS, it's unlikely there's an error in the settings. Anyway, reset it to defaults and - if the BIOS is the cause - it should be fine.
Does it still boot from the recovery media or the Windows install disc you need to fix the mess on your hard disk?
My goal was to extend my C: drive by shrinking my D: drive and then using that unallocated space for extending C. I have a single HDD. Using Disk Management, I have not reached my goal yet but in the process I switched the disk from Basic to Dynamic, thinking that dynamic disk would allow me to extend a drive with an area that is not contiguous. (adjacent to C)
I realized that switching to dynamic disk did not allow me to extend the C: drive. So I wanted to switch back to Basic disk type but I did not see a way to do so in Disk Management so I used a program called AOMEI Partition Assistant which includes a Dynamic Disk Converter. After running this disk converter that supposedly converts from Dynamic back to Basic, I was not able to boot into Windows after restarting.
At the moment, I am not sure how to extend my drive but my immediate problem is that I cannot boot into Windows anymore. The system boots straight to BIOS even though I have checked the single HDD that contains the OS/boot files is visible and that is in the first boot priority.
Can you take a look at the screenshots I took from my BIOS and tell me what the issue is?