Demo - unusual graphics problem

[Drumsfellow]

Tried in window mode and at a different resolution, still nothing.

I tried reinstalling the drivers; this time, I downloaded them from the notebook manufacturer page (as recommended here). I have an HP Compaq 6735s.
I downloaded the graphics drivers for my specific notebook model, for Windows XP (32 bit). This is the driver pack.

I first removed the old drivers, along with the Catalyst Control Center (which I haven't been able to open for quite some time now; I right-click on the desktop, and when I click on the CCC, I get an error message saying that the Control Center cannot be opened). After installing the drivers from the link above, I reinstalled the Demo (restarting the computer after each uninstall and install).

I still cannot open the Catalyst Control Center, and the game still doesn't work properly.