MEMORY Question

You can't put DDR RAM in your machine unless it specifically states that you can use both SD and DDR in the manual that came with the motherboard.
Personally I can't think of a single board that allows you to do this, but I don't know everything.

Next you need to check in the motherboard book how much SD RAM your board can handle.
It is probably 512 or more so you're OK on capacity grounds.

Then get yourself one 512 strip or two 256 strips of 133 MHz SD RAM which will be reasonably cheap, then remove the old 128 and slot in the new RAM.
Make sure it contacts properly and the clip at either end of each strip is fully engaged.
You can't put it in the wrong way around as it has keyways so it'll only go in one way.
If you only have a 100 MHz capability on your board for the RAM then don't worry as the machine will still be be able to use the 133 MHz RAM at the slower speed.
You can't put 100 MHz RAM into a machine with a non-switching 133 MHz bus though or it will damage the RAM.

With a Dell it's all pretty easy to figure out.

Go to their Hardware Upgrade WWW site and enter the service Tag number of your PC (it should be located on a tag on the side or back of the PC) and choose a "Memory" upgrade in Step 2.

After you click on the "Buy" link their system will give you back their part # and specs for the memory module that fits your machine. You'll have to decide how much memory you want to put in but you also want to match the correct memory type and speed.

Wow !
I didn't know Dell ran a service like that.
Excellent.

It's really pretty slcik. I don't know why other system makers don't do something similar. You can create an account and track your PC on their system too. All you have to do is pop in every few montsh and their site will tell you if there are upgraded drivers, etc.. for your system (for the original components only!). It's kinda nice to be able to find BIOS, Sound, Video, etc.. drivers all in one place.

I ran this search at www.crucial.com. You put in your computer manufacturer, type and model, and it comes up with what memory would work for you.

Click Here for the search results.