last night my keyboard stopped working. the caps lock key wouldn't make the light go on or anything. This morning after making a backup disc of latest work (note the mouse still worked) and installing the "go" button in my browser toolbar, I looked up Dell's phone number and called support.
The answer? pull the battery, unplug, and push the power key for 20 seconds. Then put it back together and restart.
supposedly this allowed to dissipate a static charge that was preventing the CPU from getting input. . .