Is it bad to not have a 24-pin connector to my motherboard?

[MDE]

Memtest86+ would be my next step. Let it run for at least a couple hours and report back.

 

[Navid]

You may want to download and install ATITool from here.
http://www.techpowerup.com/downloads/259/mirrors.php

It will place the GPU temperature on your taskbar while running.

Run it and underclock the GPU and memory a little bit. See if you can find a setting that gives you stable operation at slightly lower clock rates. So, you need to keep trying different clock settings and running the stress test and see if it crashes or not.

It may help to know how much lower clocks give stable operation.

 

[Josh7289]

I just did some searching on Google, because I wanted to see if anyone else was having these problems. Guess what? I've read numerous reports of my motherboard not being able to run Nvidia cards! I can't believe this! I'm calling up MSI as soon as I can.

If this turns out to be the problem that has been haunting me for almost three months and costing me time and money, I am so f*cking done with MSI and ATI. Never again will I buy any of their products.