ihatemycomputer

A little background, my computer has been acting up and refusing to play any Source engine games since I bought The Orange Box a few days ago, even though it's always played Half-Life 2 very well at the lowest graphics settings. Steam said that I needed DirectX 8 or higher to play, which is weird because I have DirectX 9.0c. I decided that getting updated drivers was a good idea.

ATI's website was no help, since they don't seem to have drivers specifically for the Mobility Radeon 9000/9100 IGP, particularly not the 7.8 drivers, which I was told were the best drivers for the 9000/9100 IGP due to their better handling of Direct3D than later versions. I attempted to resolve this problem by getting OmegaDrivers, which turned out fine for simple computer usage, but DXdiag.exe stated that my computer was unable to use D3D, which makes no sense since I had been playing HL2 days earlier and now no longer can. I learned about Mobility Modder through google, uninstalled my omegadrivers, downloaded the 7.8 desktop drivers from DriverHeavenDownloads, and ran the modder. The modder said everything was successful, but upon rebooting my computer is still running graphics through the default VGA drivers; it doesn't seem to know that I installed any drivers since I deleted the omegas. Why isn't my computer recognizing that I used Mobility Modder?

Please help me fix this problem so that I can play these games I spent a bunch of money on

my specs:
Intel Pentium 4 2.80GHz
512MB RAM
Windows XP SP2
ATI Mobility Radeon 9000/9100 IGP
DirectX 9.0c