Well, I'll tell you what I would do in this situation but you may not want to do this. I would get Linux Ubuntu on a CD and run it from the CD to see whether it would recognize the mouse and keyboard. Ubuntu can be downloaded for free, burned to a disc which is a bootable disc, and then you can either run the Ubuntu OS right off the CD, without installing it on your hard drive, or you can install Ubuntu on your hard drive while leaving Windows intact, thereby creating a dual-boot configuration.
Let's say you downloaded Ubuntu and created the bootable CD (or DVD), you boot from the disc and elect to run Ubuntu without installing it on your hard drive. Then, you can retrieve files by finding them with Ubuntu and copying them to a flash drive (if USB works under Ubuntu) or to a CD/DVD if you have a burner CD/DVD drive. Of course, you'd need to spend some time getting a little familiar with Ubuntu.
Does this sound like something you'd want to try?