Zip archive for the Gigabyte GA-G41M-ES2H desktop motherboard, an Intel G41 chipset micro-ATX board judging by the model name. At only 73 KB the package is small, so it more likely holds a compressed BIOS image or a short document than a full multi-page schematic; the name does not say which, so open it and check the contents first. If it is a BIOS dump, read and save the original SPI chip with a programmer before writing, confirm the image size matches the chip capacity, and verify the PCB revision printed near the slots matches the file.
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.