PCI-E card problem

I bought an e-GeForce 7200 GS graphics card last week and installed it
to my mother board of ECS RX480-A. Although no error message was
appeared during the installation, I found that the colors quality is
displayed incorrectly. I set the quality colors as Highest (32 bit)
but it is same as setting of 16 bit. The color bar in setting of Color
quality section is showing the transition of colors abruptly. Also,
many colors can not be displayed and the icons are displayed coarsely
when I run some softer ware such as MS office 2007. I just replaced
the card with a new one which I exchanged from the store.
Unfortunately, the performance is same as the old card. I also tried
to update the driver to the newest version which I just downloaded
from your website. Although it made the graphics quality better than
the old driver, it's still not display the colors correctly. I'm sure
that my mother board quite good any it work perfectly with other card
when I used it. So, I really don't know what is going on in this
matter. I hope get your instruction for solving the problem. Your
early replay will be appreciated!

P.S. my system and settings information as following:
OS: Windows XP pro,
CPU: AMD 3800+
Screen resolution: 1280 x1024 Screen
refresh rate: 70
Color quality" 32 bit (it is looked no difference with 16 bit. but it
much better than setting at 8 bit)