If you don't know which one to get, get the second one (no SSE). If you don't know what SSE means, read this: http://en.wikipedia.org/wiki/Streaming_SIMD_Extensions
You can use freely available tools like CPU-Z (http://www.cpuid.com/softwares/cpu-z.html) to check which SSE capabilities your CPU has.
fs2_open_3.7.2_SSE.7z (http://swc.fs2downloads.com/builds/WIN/fs2_open_3.7.2_SSE.7z) (Mirror (http://scp.fsmods.net/builds/WIN/fs2_open_3.7.2_SSE.7z)) (Mirror (http://scp.indiegames.us/builds/WIN/fs2_open_3.7.2_SSE.7z)) (MD5 (http://swc.fs2downloads.com/builds/WIN/fs2_open_3.7.2_SSE.md5))
This one is based on the SSE Optimizations from the MSVC Compiler.
fs2_open_3.7.2_NO-SSE.7z (http://swc.fs2downloads.com/builds/WIN/fs2_open_3.7.2_NO-SSE.7z) (Mirror (http://scp.fsmods.net/builds/WIN/fs2_open_3.7.2_NO-SSE.7z)) (Mirror (http://scp.indiegames.us/builds/WIN/fs2_open_3.7.2_NO-SSE.7z)) (MD5 (http://swc.fs2downloads.com/builds/WIN/fs2_open_3.7.2_NO-SSE.md5))
fs2_open_3_7_2_WIN9X.zip (http://swc.fs2downloads.com/builds/WIN/fs2_open_3_7_2_WIN9X.zip) (Mirror (http://scp.fsmods.net/builds/WIN/fs2_open_3_7_2_WIN9X.zip)) (Mirror (http://scp.indiegames.us/builds/WIN/fs2_open_3_7_2_WIN9X.zip)) (MD5 (http://swc.fs2downloads.com/builds/WIN/fs2_open_3_7_2_WIN9X.md5))
For Windows 98, Windows ME, and Windows 2000.
What are those SSE and SSE2 builds I keep seeing everywhere?
Your answer is in this topic. (http://www.hard-light.net/forums/index.php?topic=65628.0)