How do you know if Win8 is the official version?

After the release of Windows8, it seems that many versions are circulating on the Internet, but which one is the official version?

According to the genuine iso (228 ocean exchange) system image file I downloaded from Microsoft websetup There is no install.wim, and it is replaced by install.esd, so you only need to mount the iso file to check if there is an install.esd file under the source under the root directory. If there is any official version, there is no official version.

The simpler way is that the official version of the image will not exceed 2.75GB, even if it is 64-bit, it is 2.75GB, so those above 3GB will be the previous version of ……

In addition: MSDN and RTM are functionally the same as the official version of win8. They can also be activated (purchased) with the official version of the key. The students who have already installed it do not need to reload, and now the official version of iso is not good. ……