Archive named 2KM890ME-20, 1.44 MB, in RAR format. The code hints at an AMD M890-class desktop board, but the name carries no brand, revision label or file type, so treat that as unconfirmed. The suffix 20 likely marks a version, with a sibling file ending in 10. Extract it and identify the contents before use. For firmware, verify the board identification, confirm that the image fits the SPI chip, and keep a backup of the original contents.
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 @schematicslaptop. 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.
7-ZipWinRARThe Unarchiver (macOS)