I upgraded to Windows 8.1 from Windows 8 with Windows Store, which I had installed by default on notebook, when I bought it.
However, it turned out that some drivers are not very cooperative with new OS. So I want to use the Reset feature.
But, it doesn't let me do it because "some files are missing". The simplest solution would be DVD/ISO, but I don't have either.
I tried downloading ISO with Microsoft tool Windows Setup, but to no avail. When I tried mosharino's method (How to download the Windows 8.1 ISO), it denied my key because it was not a "retail" key.