Duplicate of the 450 G4 password-unlocked BIOS archive, a 4.95 MB RAR file marked (2) as a second copy. Its contents should be a modified firmware image with the password lock removed for a 450 G4 machine; the name gives no brand or board revision. Unpack it and compare against the first archive to confirm they match. Flash only after reading the original chip with a programmer and keeping that dump safe, and make sure the extracted image fits the flash chip size.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @biosfilebins. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →