User Interface not showing up

I’m having a problem with Unity, when I boot it up it loads up well, but all the windows don’t have any text or butons on them.

I don’t know what to do, here is a screenshot of the problem:

Thank you.

Found the solution thanks to “Tct” in this thread:

http://forum.unity3d.com/threads/141139-No-interface-AT-ALL/page2