Hi,
Do you have a back up image of your windows install? If yes, this would be a good time to restore from back up. If not, I suggest you slave the disk with your installation in another computer and back up anything important on this disk.
Are you able to start in Safe mode by chance?? Press F8 (tape, pause, tap, pause) during POST. I suspect not, but asking anyway.
Also confirm Correct memory size, frequency and CPU parameters look correct in BIOS under MIT. (Probably nothing to see here)
Other steps:
Open a command prompt in the Recovery Console:
Type Bootrec /RebuildBcd, and then press ENTER. Type yes if a path to your windows install is found, then test restarting normally. Results?
If the Bootrec.exe tool cannot locate any missing Windows installations, you can remove the BCD store, and re-create it. To do this, type the following commands in the order in which they are presented. Press ENTER after each command.
Bcdedit /export C:\BCD_Backup (creates a back up of the file you are deleting)
ren c:\boot\bcd bcd.old (renames the existing file with .old extension)
Bootrec /rebuildbcd (scans for a windows install, and rebuilds the BCD pointing to the install)
Once again, restart and attempt to start windows normally.
This article can be used for reference. Varies slightly from my steps.
https://support.microsoft.com/en-us/help/927392/use-bootrec.exe-in-the-windows-re-to-troubleshoot-startup-issuesJust so you have a understanding of the problem. After flashing the computer with a upgraded BIOS, it might have newer settings or parameters that were not used or available when the OS was originally installed. The boot issue and error you received can have more than one cause. Examples can be:
BIOS settings incorrect for installed OS (UEFI, Secure Boot, instead of Legacy Boot Options)
Formatting of the disk cannot be read or interpreted by the new BIOS. (example disk/partition offset)
Boot Manager missing or corrupt
Size or location of recovery partition not correct or what new BIOS is expecting.
This is tough to diagnose over the web
So wishing you luck. I suggest you back up your data before proceeding with recovery options.