RAR archive of 3.16 MB for the Lenovo ThinkPad W541, prefixed with 64, a token whose meaning the name does not explain. Board number, revision and file types are not given, so extract the archive and inspect the contents before trusting them. A package of this size often holds BIOS dumps or service documents. Compare the motherboard label with any source information included, and back up the original SPI flash with a programmer before writing an image.
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 @SCHEMATICWORLD. 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)