Cant Play GTA San Andreas on windows vista

[transformers12]

I got windows vista sp2 but then i downgraded to vista sp1 to see if it would fix the problem but it didnt. It also said i needed Direct X 9.0c But i have vista with direct x 10 and i cant downgrade to 9.0 also when i try playing it says c:\windows\system32\dciman32.dll is either not designed to run on \windows or it contains an error.Try installing the program again using the original installation media or contact your system administrator or the software vendor for support] on the top of the window it says gta_sa.exe-bad image does anyone know how to fix this .I just want to fix it so i can play the game and put new mods in if you now the answer that would really help!!!!!!!!!!!!!