I have a 5 year old Dell Inspiron 530 desktop computer which is slowly grinding to a halt. Someone told me if I put extra RAM in it will speed it up. On the motherboard, there are four slots but only two has memory in them and they are 1GB each. If I bought another 2 RAMs of 1GB each and put them in the free slots would it speed the computer up (would it be twice as fast?) and is it as simple as just putting them in or is there other things I need to do?