Need urgent help related to XGX8600Gt problems

[atb]

Hi guys... firstly i would like to introduce me as a new member...
ok...i recently got a new system...specs are as follows

motherboard:gigabyte GA-G31M-S2L
cpu: core2 duo @2.8 ghz
kingsten 4gb of ram
western digital 320gb sata hdd
XFX 8600 GT card

I am having problems with my 8600gt....
I am having 2 DVI display outputs..and have got a DVI to VGA converter with the card.....and i use the converter to connect it to my vga pin....
when i fit my 8600 gt in my motherboard and boot i get all text and colors garbled up in the start bios screen....also my window display is the same....ie at the lowest color setting ie 4bit and garbled....
i tried to install the drivers from the cd...but in vain.... my device manager always shows a question mark for 8600Gt in my device manager...even after installing the drivers...
when i switch to onboard graphics all works fine....
I checked bios it is set to detect pci graphics if it is plugged in otherwise it will use onboard graphics...
Is this due to the DVI 2 VGA convertor or adapter???
can any one please suggest me some solution to this....its a new system and i have not able to played a single game on it....

[surinder]

Remove your GFX card on power off stage Reinsert it properly and reinstall drivers. If problem still remains contect your vendor for replacement.