Make sure there isn't a key stuck down,also check you haven't accidentally turned on sticky keys.You can check this in control panel/ease of access center/make the keyboard easier to use/set up sticky keys.
Looks like the windows key is stuck down,im using windows 7, using a wired keyboard. Randomly today started doing shortcuts i.e:
L = lock system
M = show desktop
E = My computer
No idea why its doing this and even the virtual keyboard does it.... HELP!! BTW checked its not sticky keys or anything else ion ease of access...
All the things you have mentioned are consistent with a dodgy windows key.alt control and delete don't work either :\