If you are looking to download a replacement file for a mod or to restore a corrupt original, follow these general steps found in community guides:
The official contain updated .res files. Download these from reputable archives like PatchGame.com or FileHippo (old version) . Extract the patch using 7-Zip; inside, you will usually find a fresh Weapons.res . Igi 2 Weapons.res File Download
locate the Weapons.res file (often found inside a subfolder named COMMON or WEAPONS depending on your game version). If you are looking to download a replacement