what i ment was, can i use winzip for this, or do i have to use 7zip or winrar?

also,

i typed -mod= @31stwwa2 in the target box, computer asked me to verify and i did when i started the game nothing happened and it went on with the normal unmodded game, what am i doing wrong
I think you made an addons folder inside the mod folder and in the addons folder you added the 31th mod folder in which the addons folder is......and thats wrong.

i made a 31st mod folder and inside that i made an addons folder. i put the .pbo files inside the 31st mod folder