three set of dlls - which one to use in my program package?

[FS Lover]

I have qt 4.5.1 installed on windows with mingw.
I found that there exist two set of qt dlls like QtGui4.dll in my installation.
a set of qt dlls in <qt dir>\bin and another set in <qt dir>\qt\bin.
and there exists three mingwm10.dll files too. one in bin directory another in qt\bin and the other one in mingw\bin. they are different because their size don't match.
I want to know:
- why 2 or 3 of one dll exist and what is the difference between them.
- which ones should I package with my qt programs.
and I think all these make other users confused like me.

[lyuts]

I have Qt 4.5.1 installed too, But there is no such dir <qt dir>/qt/bin, I've got only <qt_dir>/bin.

Did you run configure with some flags? and then 'mingw32-make', 'mingw32-make install' ?

[wysota]

I have qt 4.5.1 installed on windows with mingw.
I found that there exist two set of qt dlls like QtGui4.dll in my installation.
a set of qt dlls in <qt dir>\bin and another set in <qt dir>\qt\bin.
and there exists three mingwm10.dll files too. one in bin directory another in qt\bin and the other one in mingw\bin. they are different because their size don't match.
I want to know:
- why 2 or 3 of one dll exist and what is the difference between them.
- which ones should I package with my qt programs.
and I think all these make other users confused like me.

One set of Qt libraries is to run Qt Creator (as it is distributed with a bleeding edge functionality of Qt) and the other set is the "proper" 4.5.1 set of libraries that you should use.

[lyuts]

Oh, that means FS Lover has installed not just Qt but Qt SDK. Got it.