You can find out all the details you need form the owners manual. Read about upgrading memory.
Now, the first step you need to do is see if that 1866 memory will work by removing your current memory and only put in the new memory. If you have problems with that, I don't think that memory will work.
There is a good chance that RAM won't work with your PC, it's a bit too high end. Take out the new RAM, check for a newer BIOS for the system and install it. Then install only the new RAM and see if it works. If not, get a stick of the same speed as the old RAM. You are better of replacing the existing 2gb stick with two 4gb sticks so they run in dual channel properly.