Well i have Skyrim on my PC and when i start it, only a Steam window appears that its starting and then the launcher comes again. And it repeats always. On the launcher i go on Play and it opens the launcher again. Does anyone know how to fix it? -_-

Hmm, we can't help if you don't post you system specs. or try reinstalling the game...
If it does not work... try asking google the best solution

Hmm.. I didn't use a Steam install for mine. But mine did something like that. I just had to delete it and reinstall and it worked. I would try that, or if you are running on Win7 make sure you install with Admin.

Uninstall and reinstall is your best bet, but back up your save file if your like your, which is usually in documents on window, possibly under my games or saves. I think you can stop it from deleting your saves when you uninstall it depends on the game, so i'm not sure.

Edit: Bliss nailed it on the head, read the gamesfaq thread, i'm pretty sure thats your problemma.

http://www.gamefaqs.com/boards/615805-/61127721
http://www.thenexusforums.com/index.php?/topic/472099-skyrim-wont-load-save-files/
http://www.minecraftforum.net/topic/820349-skyrim-wont-start/
I strongly recommend you read a few of these, the first link talks about a steam window; i hope this helps without you having to lose your files.