How to make my application run in windows 7

interface, environment, design everything in windows 8.1 is far different from windows 7.
you are developing the application in windows 8.1 environment but you are trying to run it on windows 7.
even the .net framework is totally different in these two windows operating system.
one way for this is, you can use third party controls like telerik and dev express then the look & feel should be same in both the os.
the second one thing you can try is, installing .net framework 4.5 in your windows 7 os. i am sure whether this will work or not but at least you can try this.