Yes, it is possible to run Android apps in Windows 7 with the help of an emulator. For instance, Bluestacks is a recognized emulator which allows you to install APK files in an emulated Android environment. The emulator is using latest and most stable Android version. Nowadays, it also support Google Play Store which makes it easier to install Android apps directly from the official store. Visit its website, download and install it then you will be able to run APK files in Windows 7.
