I do a lot of formating and reinstalling as I work with Windows 7 OS stuff so I have to compile, install and setup everything again and again..
What does the fact you work with W7 has to do with reinstalling again and again??

Is there a way I can compile everything once and then create a setup file for that version like the standard Qt MinGW version that is available on website..
Do you mean install for your application or Qt?
You can have various versions of Qt in parallel, you just have to specify the correct paths in your project, to the Qt version you want to build that project with.

However, if you are building for various platforms, one good way is to use virtual machines to test deployment - with out the need to really format an reinstall you own system.