Can someone again help me.

I´m new at this things and i`ve downloaded everything as said in the forums
first patch 1.2,full 5.4 mod (including 5.2,5.3 and 5.4.1 patch but when i try to play the game i get something like this: "can not run because can not find MSS32.DLL. I`ve reinstalled but nothing.

Probably it`s better to give up but all of you say it`s a great mod!!!!