I have just started and I have to knock out these two things so that some field will be gone and its safe to leave, I went to the left one and I have taken out all of the squads, all of the porters and done all the the servers as well as knocking out the underground genarator...

But know I don't know what to do, I have used a normal and sniper on almost everwere and nothing happens...

What do I do?

Go to EPS2 and find the runway. Ada will say about some controlling divice .Go and get it and go to Town 2. The two frames lying on the ground go to the evil one and you can control it!!!!!! Then you can go through the force field. You'll Know when You play.