Windows 2000 Professional

One of my workstation running windows 2000 Professional is acting strange. The Keyboard and the mouse are not functioning at all. I tried to boot with a 98 bootable diskette and I noticed that the Keyboard is working fine. I deducted that I may havea security issue that will explain the keyboard and mouse behavior under Windows 2000 professional.

If somebody knows what is going on it will be nice to share it with me.