Question: How to remove projects from qt creator, I can delete files from project view but I cant delete my .pro file and my main project folder.

Answer: 
It's a littel dirty way, but go (on windows) into the `AppData\Roaming\QtCreator.ini` file and in `[ProjectExplorer]` remove the projects from:

* `RecentProjects\FileNames`
* `RecentProjects\DisplayNames`

On restarting QtCreator only your needed projects will displayed. 

For Linux, edit `~/.config/QtProject/QtCreator.ini`
I found a way, delete the build-*projectname* folder its in the directory in which your project was saved.