AVX is a Floating Point (for SSE) algorithm that can do 1x 256bit SSE executions in one cycle or 2x 128bit (or 4x 64bit) in one cycle. Its present in SandyBridge, IvyBridge and AMD FX Bulldozer.
Any earlier cpu can do only 1x 128bit (or 2x 64bit) in one cycle. So this means if you DONT have the processors above you CANT run the showdown_AVX.exe

So there you go, the game makers aint stupid. You just have to upgrade the CPU if you want to run the AVX mode.
This ALSO means that if you can't play on AVX mode the trainer aint working for you eather!!

Glad I could help ( a bit late but yeah )

[Edited by Triggy-finger, 11/12/2012 3:10:14 PM]