Error: Qt Creator needs a compiler set up to build. Configure a compiler in the kit options

[khanhmg]

I've just installed Qt Creator and run my first program. However, an error occurred: Qt Creator needs a compiler set up to build. Configure a compiler in the kit options. I've googled it and found that some people also run into this error, but I don't know exactly what to do because I don't really understand it. Can someone show me how to get rid of this problem? Thank you.
Here are the screenshots:

[Chris Kawa]

You can't mix and match Visual Studio versions. You've got a kit set up with Qt compiled for VS2013, but only VS2015 installed.

You can either install VS2013 and use that or compile Qt with VS2015 yourself and setup a kit for it.

[khanhmg]

@Chris-Kawa How can I set a kit? Could you tell me briefly how to do it? Thanks.

[Chris Kawa]

If you're new to this I would suggest just using VS2013. It's the easier option.

If you want to use VS2015 you will have to first build Qt from source, as there's no precompiled package for that version. then You need to add that build to Creator and the set up a kit.

[khanhmg]

@Chris-Kawa Thank you very much.