without showing your motherboard specs, we have no idea whether your system can support DDR2 or not.
but probably can because u r said u are using now~~~
Judging from those two screenshots, am I correct in assuming that your computer is very new, and very high end as well? I say that because both DDR2 (your RAM) and PCI-Express (your graphic interface) are very new technologies.
The RAM that you gave a link to would not work in your system. The RAM in the link is DDR RAM, and has 184 pins on the actual module itself. The kind of RAM that your computer uses is called DDR2, and it has 240 pins on the module. The RAM in the link would not fit in the slots in the motherboard.
The RAM that you show is the right RAM for that motherboard and chip set. That is a very new system, I didn't know that Dell had jumped on the intel 925X chiipset bandwagon.