Zip archive for the Gigabyte GA-H55M-UD2H desktop motherboard, an Intel H55 chipset micro-ATX board. The name does not say whether it holds a schematic, boardview or BIOS image, so open it and check the contents before planning a repair. At 1.76 MB it could hold a BIOS file or a compact service document. If it turns out to be firmware, back up the original SPI chip with a programmer before writing anything. Match the revision printed on the PCB near the slots against any revision noted inside, because Gigabyte boards change layout between revisions.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.