Video Card Problems

This is a really hard question to define as I am not completely positive as to the origin of my video cards problems.. But, my video card is an ATI Radeon 9800 Pro, and has recently been giving my many migraines because after I boot up my computer and it goes to the Welcome screen with the scrolling bar as its loading, my computer will reboot after window. So I would take my video card out and put it in, blow on it and sometimes it would miraculously work.. But after awhile it stopped so I switched the V/C out with another of the same model and it is working, but my graphics are choppy, when I boot up it pixelates and will kind of make a wave across my screen fixing the pixelation. My computer is running rather slow, and so I thought i'd look at it in DXDiag and see what the problem is - i've already gotten the highest driver for this video card - and DXDiag says that Direct X Features are unavailable, my Approx. Total Memory is N/A when I know very well it is 128 MB, i've passed the DirectDraw tests and I pass with flying colors.

Another odd thing about my issue is that my driver came with something called EarthSim, i thought i'd load it up and so I tried, 2 or so steps into the installation it says I require 64 mb of video memory and that I don't have it... So i seem to have quite a conundrum on my hands and am praying that someone on these boards will be able to understand and answer my problem.

*edit* I also forgot to mention that it says my DDI Version is unknown, but I think this is direct x ? which i have installed to 9.0c