What were you running before? Or is this a new build?
Did you build this rig? Is so, your motherboard would have come with a driver disk. You could use the driver from there to allow your USB to work......so you can use your mouse/keyboard & access the internet.
Then update all your drivers from the manufacturers website.
If you didn't build it (or don't have the disks), it will be difficult. You can't load anything to USB from another computer to update your drivers.
In that instance, you'll need to hook up to a wired LAN connection to access the internet. Use your keyboard to open Windows Update (it'll be tricky if you're used to primarilly navigating with a mouse, but more than doable) and let Windows Update do the trick. There will be lots of updates from a clean install, but eventually it'll install your (well, at least a) USB driver and you should be good to go.