I wiped my computer clean, and no usb/audio compents work, help im a noob i can admit it.

Title pretty much sums it up. I used the two reboot disks that came with the computer ( Emachines). Well after starting up after the "clean" none of my USB ports work and my audio wont play. Its like the computer wont "pickup" the drivers, its about 3 years old, its a W3502 desktop. I was using a usb mouse but it wont pick it up now. I did notice that while the computer is turning on the usb light comes on indicating the mouse and usb ports are working but when i see the "windows xp" startup loading screen it just quits working any ideas???
Thanks !!