If you have a 4-year old laptop melly, chances are that if you are looking to capture the speed of computers today you will need to buy a new one.
If you are looking to stay with a laptop, I think another Dell laptop would be a very suitable choice, and prices are quite competitive at the moment since HP and Acer both released "cheap" laptops. I would recommend looking at those options and if you so choose to purchase, running Decrapifier among other things after you got it.
Two things that I notice here as far as advice goes:
1. You are getting help from some of the brightest people about computers, and some of your questions are VERY easily answered, with no wait time, by typing 2-3 keywords into google. For example, you could've looked up your Dell laptop make/model and found out what all of the compenents were (including the RAM type) very easily.
You are grateful, and it's good, but if you actually take time to research the problem yourself you will learn things about computers and end up becoming an "expert" as well! Any time you have a question, like this last one
will shutting down your computer every once and a while help its speed and memory performance?
check google and see what you find first, and then come here and ask if the answer doesn't seem sufficient.
2. Be careful about what you install and what you run on your computer. Different programs will always come with other useless programs, like ITunes coming with some sort of internet toolbar, and Winzip trying to get you to install something similar as well. When you install something, make sure you don't have ALL the boxes checked, and make sure you know what you are installing. Google "is" your friend, and can tell you what the programs are.
Maybe its conservative to say, but to give a man a fish is to feed him for a day, but to teach a man to fish is to feed him for a lifetime!
-j
