Line of Sight: Vietnam? I run Windows 7 (64-bit), and have never had the Steam version, v1.04, crash on me, but whatever they did to update the game also broke it. Floating corpses, glitched out crawling enemies, you get stuck on objects in the game environment more often than in previous versions, the server browser can't be revived with the Qtracker GameSpy fix, and GameRanger doesn't recognize the new executable. It's a mess. Unless they fix it, I would avoid the Steam version. If you still have a retail copy, stick with it and the latest retail patch, v1.03. The only nice thing about it, that I noticed, was the addition of widescreen resolutions in the video options, though custom resolutions are attainable in previous versions through editing a configuration file.
Just saw that Retroism also re-released Elite Warriors: Vietnam on Steam. Not sure if they updated it, but I'm hesitant to buy it. Just found a copy at a Goodwill store, anyways!