HP 15 file for the X12a platform, 335 KB in RAR format. X12a appears to be an ODM project code, but the name gives no full board number, so confirm compatibility against the PCB label. The size points to a BIOS image. Read the original flash chip with a programmer and keep the copy before writing, and check that the image size matches the chip capacity. Open the archive with 7-Zip or WinRAR to check its 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 @hrtechno. 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)