HP archive referencing a Quanta U83 board, 409 KB in size. Quanta is the ODM that designed and built this mainboard for HP, and U83 is its project code. A package this small most likely contains a BIOS or EC dump rather than a full schematic. Open it with WinRAR or 7-Zip, then compare the image size to the SPI flash chip on the board. Confirm the U83 marking on the PCB and save the original chip contents with a programmer before reflashing.
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)