USB Keyboard Mouse not working

Hi,

I have dell dimension E520 with usb keyboard and mouse. I shifted that machine from one place to another place. After attaching all the cables when i powered up PC found that keyboard and mouse is not working.

It displays the new hardware found wizard but how should i install drives both keyboard and mouse are not working. I spoke to dell people they said to reinstall the OS. But just for curiosity wanted to know is there any other way where we can install the drivers without reinstalling OS.

Your help will be appreciated

Dhiren