see link

Here is a link that might be useful: support.microsoft

I might go by Crucial and let them scan my computer to see what it says about max memory and module pair arrangements.

Here is a link that might be useful: http://www.crucial.com/

The other thing is, unless you are using a 64 bit application of Vista, your computer will not see and use all 4GBs. The most it will see and use is in the order of 3 to 3.5GBs.
The other concern is whether or not your computer is even made to accept 4GBs. The best way to check on total memory a computer will accept, is to go to crucial.com as suggested

Some motherboards offer 2 pairs of RAM sockets for 2 distinctly different types of RAM. These are usually 2 different colours to aid recognition. With these it is not possible to populate all four modules, they are designed so a person has a choice of RAM types.

I did a "crucial scan both before and after adding memory.
the only difference ( except for the slight difference in memory was that the 2 1024 MB were shown with the 2 empty banks.
Here is the "After" scan.

Here is my system info.I don't understand the difference between Physical memory and Virtual memory

Physical memory is the RAM. Virtual memory is hard drive space that can be used as RAM (much slower).

The crucial scan shows that you've got 2 1 mb and 2 256 kb chips. It also shows that one of each of these is DDR3200 and one of each is DDR2700. That doesn't make a lot of sense.

Can you post the results of the before scan?

Did you make sure to get the same speed RAM when you got the new RAM?

bpgreen,
I didn't know there were different speeds of RAM. I have no idea what I have. My son installed them for me. I figured he knew what he was doing.
Also when I snipped the "before scan" I didn't save it correctly so it isn't jpg, but is in my documents. So I can't post it.
However, it shows 2 banks in one row each 1024Mb, no DDR numbers, and the 2 empty banks below. The rest is the same, except for the difference in "Currently installed memory" (Old was 2048mb) and #of slots available, etc.

You might want to download the standard(free) version of Siw ...

It will attempt to tell you exactly what is in each slot, and what each slot takes too.
!~
my slot 2, toshiba laptop;

Here is a link that might be useful: SiW System Info for Windows

I made a mistake in my earlier post and divided everything by 1024. I should have said 1 gig and 256 meg.

If I were you, I'd try narrowing things down. I would first take out the original RAM and put the new modules where the original modules were. See how much RAM is reported. Also see if it reports the speed. If that shows 2 gig of ram, then the new modules are the right size. If it shows 512 meg, then the new modules are 256 meg modules instead of 1 gig modules.

Then, try putting the original modules in the slots where you currently have the new modules. See what is reported when you have it in that way.

bpgreen,
The package with the new modules states "Two 1 GB modules".
My son seems to think it may have something to do with the "Bios"and/ or motherboad, needing an update???? I have emailed DFI- DS told me to. They responded with a list of things they need to know to help me that is beyond my capabilites so I will wait until my DS can get to me.
Thank you all who responded to my plea. I'll let you know how it works out.
Meanwhile everthing is running smoothly.

Just an update:
Rotated the chips in every possible configuation, determined that the bios drivers etc. were up to date. No go on getting increased memory, so returned the chips (Corair) and purchased 2 Kingstons for $10 less.

Inserted new chips, did a scan and everthing is fine.

That's good to hear. Sounds like you just got some bad modules.