|I third the keyboard being the problem...|
It actually sounds like your windows logo key is stuck down, when you hit the "E" key and the windows logo key at the same time explorer will open. That is assuming you have a windows logo / start key on your keyboard.
Short-cuts with windows key + other.
windows key + "E" key = shortcut to "computer" (explorer window)
windows key + pause / break = system properties window
windows key + "M" key will minimize all windows
windows key + "L" key = change user (vista only?)
windows key + "F" = search window
windows key + "D" key will show desktop
windows key + "R" key will open run box
If these are the kind of behaviours you are experiencing while typing (try typing some of the keys without holding the windows key down) you may have narrowed it down.