Windows 10 comes with .NET framework 4.5 pre-installed, but many apps developed in Vista and Windows 7 era require the .NET framework v3.5 installed along with 4.5. These apps will not run unless you will install the required version. When you try to run any such app, Windows 10 will prompt you to download and install .NET framework 3.5 from the Internet. However, this will take a lot of time. You