Windows 8.1 update won't work

Hey Guys :)
I want to update my Windows 8 to Windows 8.1 again, because that fuck shit AMD CCC bugg on my PC. I already updated my Windows 8 to Windows 8.1, AMD CCC worked fine.
I cleaned my PC and now I have got again Windows 8 and I want have it Windows 8.1.

But my problem is: I can't find the update on the Store. I only can update it form Store.
I already tried this: http://windows.microsoft.com/de-de/w...d-update-store
On this link there are causes why it can't be find in the Store. Nothing helped.
I have got Windows 8 64-Bit System, does somebody know why it can't be find in the Store?

If you disabled UAC, the store doesnt even open.

Also, there are a few .iso-s out there, mostly N editions as those do NOT come from the store (out there = piratebay, but as you have a serial for win8 which allows you to upgrade to 8.1, its not illegal i suppose)

The reason why I can't find Windows 8.1 on the Store is: I didn't allowed to update my PC automatically. I updated the PC and now I can find it.