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 not possible to remove .pro files from QtCreator. There is an option as shown on screenshot, but it doesn't work.

![enter image description here](https://i.stack.imgur.com/c4rxS.png)

You're not able to completely remove your project for QtCreator. For this you'll have to close project first and manually remove whole folder with .pro file. But to be serious no .pro file means no Qt project at all. qmake won't be able build project for you without it.
As time has passed, it would be helpful only for the future generations, but still:

**If you're deleting subprojects,**
you can delete .pro files of the subproject manually even without exiting the QtCreator: delete the project folder, then remove the line from the main .pro file where your subprojects are listed, then run qmake.

**If you're deleting the main project,**
(if you want to delete the main .pro file from the project itself), it's a little bit unusial, you won't be able to build the project, but if you still need it, Andreas' way will do.