I have create a Small WPF C# Program with VS2012. it is run successful in Win 7 and Win 8 , 32Bit and 64bit but it have trouble with windows XP and after runnig exe file This message is displayed: program is not valid win32 What is the solution?
you should reduce the target framework of your Project. VS2012 runs with .NET 4.5 as default, Windows XP does not support anything higher than .NET 4.0.
You can go to your Project Properties and select at the tab Application the Target framework.