I am trying to install new memory in my boss' computer. The older memory was 1GB in 2 dimms - I bought him 2 more DIMMs of 1 GB each.
When I open his computer I see 4 slots. The old memory seems to be using slots 1 and 3. Is this normal? Now, since the new memory is bigger but same speed, do I put the new memory where the old one was and put the old one in slots 2 and 4?

I am not that familiar with it but I think the biggest issue is compatability more than position. You may try various positions to see what works best.

Totally normal. Put the new where the old was or in the other slots. It should not matter.

so I could put 512, 1, 512, 1?
I don't think I should... don't they always talk about "pairs"? I thought I was supposed to put 1,1,512,512

most motherboards these days have the "pairs" alternated due to the motherboard traces.

Regardless, looking at the motherboard (or the manual) should tell you where to place them for the pairing.

Yup, you're probably right to alternate them. The slots may even be alternating colors. That's very normal these days.

awesome!!! I did it!!! and now the computer is VERY fast. Thanks all!

Good suggestion. I'll go find the wife now

I would find time to parse what programs start up when the system is booted. The typical "piggy" MS OS will in time waste the additional memory, especially if a program like Office is loaded automaticly.

Office programs always seem to slow my computer down..luckily I am not a heavy user of it

This is a new computer with Vista Business in it. My boss hated it and so did I. Now it's fast, almost worth having Vista.

It will take some getting used to. Also, I've been recommending at least 2GB RAM for Vista along with using at least a 1GB flash drive to take advantage of ReadyBoost.

You could run CPU-Z and check to see if the memory's running in dual-channel mode.

not sure, but is that a good thing?