Following app should be closed before continuing d install?

Question

Hi All,

I am working on WPF application. While installing the setup of App I am trying to run another process, through Install()method of installer class and while uninstalling APP same process is going to kill in Uninstall() method of installer class.
While uninstalling the App, below error is occurring, Please help me out how will I remove 
the following applications should be closed before continuing the install?

Thanks