Problem playing unpatched version (activation.x86.dll)

I bought dead space 2 on origin and noticed that every dlc weapon was already free in the shop, and every ammo blueprint was already found. After a bit of searching around I found out that you could replace the deadspace2.exe file with an unpatched one to play without dlc. But when I replace the new file with the old one I get a system error because activation.x86.dll is missing.

I've been trying to find a solution for a while now but nothing seems to work. Does anyone here know what to do?