The game was built for 4:3 monitors. You may need a "Widescreen Fix" (available on PCGamingWiki).
Unless it is the 2008 Army-sponsored version, downloading the game for free from unofficial sources is considered software piracy. 5. Technical Compatibility Tips full-spectrum-warrior-pc-game-free-download-full-version
If you want a version that actually works on without the headache of broken ad-ware, the following digital storefronts carry the optimized "Gold" or updated versions for a very low price (often under $10): Steam: Often bundled with the sequel, Ten Hammers . The game was built for 4:3 monitors
If you do acquire the game (legally or otherwise), you may face issues on modern PCs: full-spectrum-warrior-pc-game-free-download-full-version
You might need to enable Legacy Components (DirectPlay) in your Windows Features settings.