Well there's your problem

. You formatted the computer, which means you erased all the drivers it had installed. So you'll need to visit the manufacturer's website for each component and download the latest drivers.
We need to know:
The make and model video card
The make and model sound card
The make and model wireless adapter
-OR-
The make and model of the laptop itself
In order to steer you to the correct websites.
Also, if you could go to "LEFT CLICK 'My Computer' > Properties > Hardware > Device Manager" and tell us what listed there has either an icon with a red 'X' or a yellow '!', that would help us determine if there are other components that need drivers other than the three listed above (I know you didn't say video driver, but chances are you're running the WinXP default, and still need a specific device driver for your video adapter).