This is how to replace RAM in a PC. It just takes a few simple steps to do this, it is really not that hard. You can trust me since I have an a+ certification in computer hardware and software. I know what I am doing, I am an expert.

1. First of all, you need to shut off your computer. To do this press the power button on the front of the computer after you have shut it down from Start> Shutdown on your start menu.

2. Unplug the power cord from your computer. This is the big black/white/grey plug that plugs into the power supply on the back of your PC.

3. Unplug the rest of the wires from the back of the computer.

4. Find a sturdy flat surface on which to work on.

5. Unscrew all screws from the back of your computer except the power supply screws. You will make a mess if you unscrew the power supply screws.

6. Open your computer up by taking the side panel off, or sliding the cover off. It might be difficult but it will come off if you have taken all the screws out.

5. Now before touching anything inside, it is a good idea to hook up to an anti-static wrist strap. If you dont have an anti-static wrist strap, just touch the side of the computer where it is metal to deshock yourself. Then when you touch the inner components you wont risk damaging any of them.

7. Find the RAM, it should be a 4 inch card sticking out horizontally on the motherboard.

8. Once you find the RAM, find the clips holding it in on either end of the ram, hold your thumb over both ends of the clips and firmly press down on the clips. They should pop the ram out.

9. Remove the RAM.

10. Now that you've removed the ram, the next step is to reinsert some new ram into your ram slots. To do this keep the clips on both sides open, and slide the ram into the slot if it doesnt want to go in you might have it going in backwards so try both ways until you get a good fit. Make sure the ram is not lopsided when its clamped down or it will not work.

Thank you, happy computing!

Source from here http://www.trap17.com/forums/Replace-Ram-Pc-t27796.html

And pictures below at links:

http://www.fonerbooks.com/r_ram.htm

http://computer.howstuffworks.com/ram6.htm

zep 516 -

Much obliged. Wish me luck.

Bejay

note that on many computers to open the side panel you do not have to remove any screws other that the 2 (usually) that hold that side panel in place, so be really careful about removing screws on the back.
Here are a few sites with good pictures and even a video
Install RAM memory & give your PC some speed
Install and Remove RAM

this video even shows how to do it on a dell pc
How to Add RAM to a Computer : How to Install RAM
by the way in that video he says most dell computers do not have screws holding the side on it just slides off.

Dells can be different. You didn't say what model your Dimension is. I have to lay mine on one side to open. Do a google search for Dell Dimension _____ manual(put the model number where the blank is) and you will find a link to the manual for your computer with complete instructions for installing RAM.

Thank you again. Haven't installed it yet, as our family is having problems with making network connections with linksys/Network Magic set-up. We somehow "lost" my GD's wireless connection, and it is fun, fun, fun. I have SOME knowledge of installing software, but GD and son are both fairly new.

But we will work it out, and chalk it up to another of life's little "mountains" to overcome.

Bejay

Bob may well be right about opening a Dell. I recently had an Optiplex 520 slimline to open and there was a small sliding gizmo on the top at the rear I need to slide backwards and the left side just fell off super easy.

Your post suggests you bought just one stick of RAM. If so and there is only one stick inside but 2 slots available then move the old one to the second slot so your new, probably bigger capacity, stick can go in the first slot for a slightly fast experience.