Not so. I have done a repair reinstall enough times without that ever happening to me. The only thing which will need to have updates reinstalled is the operating system. You can do that either by...

Well if you do try it, it will first of all ask you if you want to try and repair it with "recovery console." The answer to that is probably no, unless you know what you are doing. A little later on...

Because one of the first things which will happen when you begin reinstallation is that the operating system will load drivers for the mouse and keyboard from the CD. The fact that you can get into...

Can you get into the BIOS? If the keyboard works there, the answer is probably that your operating system needs reinstalling.