What is the problem?
We cannot know. Informational caloric value of your post: zero. Watch the splash screens and tell us at which point the app launch hangs. In addition, provide detailed system info. If it hangs on MediaCore, we need to know what CoDecs are on the system. I already get this ugly feeling that you installed K-Lite or some otehr crap and now nothing works anymore....
1. plug in , remove them one at a time
2. bad file, use a different file and see