Windows 10 has been recently launched and at the same time this operating system has become popular because of its cool look as well as performance. But along with the positive side of this Operating System, it also has the negative side of it. The most common and most frequently occurring error message in Windows 10 is 0x803F7003 error, and at the same it will not allow you to download any app from the Microsoft app. There is no reason to worry as there are ways by which this error can be fixed. But before that we should know the actual reason for this error.