hm, in this case I'd say uninstall Enderal completly,
and either reinstall Skyrim, or at last "Verify Integrity of Game Files" (or...whatever it's called in english - you know what I mean)
then start Skyrim and see if it works as it should.
then reinstall Enderal.
sucks, but other than that...
(there are instructions on how to use both games more or less at the same time
if you're interested in that;
I also could type out what I did

)