execution problem on different systems

Hi,

I want to know how to make my c# project to execute on any windows system. My project is written in VS 2012, i have chosen .NET Framework 4.0 in target platform so that it can run on windows XP SP3, Vista, Windows 7 SP!, Windows 8, Windows 8.1 and Windows 10. in Build I have chosen x86 so that it can run on win32 systems also.

In app.config file I have mentioned the following:

while executing on windows XP sp3 where .NET Framework 4.0 is already installed, there is an error while installing itself. the error is "Cannot continue, the application is improperly formatted."

I want to know how to resolve this issue at the earliest.

Thanks in advance.

Husain