Saphire 5450 hd ddr3 run on ddr2 motherboard ?

DDR3 Video RAM is different than the motherboard RAM. They are both completely separate systems.

And yes, it will run in your system, this 5450 uses very low power.

ok thnx for the reply , but the real problem is my monitor going blank when i plugin my graphic card  

go into safe mode (sorry it was boot mode, but I meant safe mode) and have you updated the driver?

If that doesn't work, do you have another PCI slot you can use?

I think he needs to down load the AMD drivers and take out the nVidia drivers and he might have to disable his integrated GPU. Just a thought

DM186, good catch  , it is an older motherboard, so he may to disable integrated GPU.

how to disable integrated GPU  

Go into your BIOS once

You restart your computer, as soon as it starts booting press F8 or the delete key. It should bring up your BIOS screen. Then you move around with your arrow keys, Enter (selects a menu option), ESC (go back out of an option). You have to find something that that says Display or Graphics Display then change it to PCI as primary display, after that to save it might be F10 (not too sure on your BIOS). Also, find integrated graphics if it has it and disable it, if it's there.

DDR2 is your board's RAM slot it doesnt really matter when they are diffrent so yes you can use it

thnx fantastik250 , lemme check this things , plz wait........

ahhh nothing found like graphic or graphic display on my mother board BIOS settings....   remove nvidia drivers restart and plug-in the graphic card but still blank screen...
< My motherboard is Gigabyte 945 S-series >

Do you have another display port (another connection on the 5450) you can try on the video card?

nop! only 1 CRT poRT ..

Do you have another PCI slot you can insert the video card in?

umm sry only 1 PCI slot   ... but my previous graphic card was run smoothly whenever i plug-in...

Okay, just being extra cautious. Hmm, is it possible for you to try the card on someone elses computer? It may help figure out if the card has problems.

Yeah if you tried the drivers and disabled the integrated GPU or just disabled it. How did you get the new AMD drivers in? Did your GPU come with a disk? If you have covered all that then I would do what fantastik said try the card in another rig.

Your card might be bad. I have another question what games are you planning on playing with that card? But first lets get you up and going. Let us know what you have done so far.