I have 2 questions.
1)I have an application file.First I see my main window and then I can press a button and
another window opens.After the second window finishes the extenuation I can still it .Can I pragmatically define that every intermediate will be closed
2)Is there any function in Labview that checks if a certain library exists in my computer?
I couldn't find such function.
1. If the intermediate windows you are referring to are subVIs called by your main VI then you can programmatically get the front panels of the subVIs to close by writing a true constant to the Close After Call VI Property node.
2. I am not aware of a single function that checks to see if a library exists, but here is a link to some documentation about how LabVIEW searches for a library when it is called:
The first related link at the bottom of this article (LabVIEW 2011 Help: Specifying the Locations of Shared Libraries on Disk) includes a section about how LabVIEW locates missing shared libraries. You might be able to use part of this process to find a particular library.