ladybridgeport

Whenever I install a new program on my toshiba Satellite labtop computer with XP pro (non 64-bit), my taskbar, start menu, window boxes and everything turn the color of windows 2000. I have to select windows 2000 desktop settings then switch back to Windows XP display. Sometimes it doesn't work and I have to repeatedly restart the computer and switch the display settings between 2000 and xp so it goes back to the normal xp display. I formatted my hard drive and reinstalled the operating system many times, Even tried a new hard drive since the old one was faulty, yet the same problem occurs. When reinstalling the operating system, it doesn't do it until after SP2 is installed. Not sure if SP2 has any affect or not. Note: Toshiba had a recall for the ram memory chip. They sent out a replacement, but I never sent back the old chip in order to have twice as much ram. Does anyone know what the problem is?