Did you restart your computer after installing? Did you install and are you logged on with an administrator account?
"but when I am trying to open an application nothing happens."
What does this mean, exactly?
Yes, I installed as administrator and restarted computer after installation.
"but when I am trying to open an application nothing happens." means:
When I click on FileMaker Pro.exe the application would not open and there is no hour glass or any error messages.
I thought maybe some files were corrupted, so I uninstalled FMP 13, cleaned the Registry, downloaded fresh trial version and installed it again.
Presumably you mean that you double clicked the application and not just clicked it, but since that's what you describe, I am making sure...
FileMaker Techsupport is Free when it's an installation issue. I recommend that you call them and let them walk you through different things you might need to check in order to resolve this.