OK PEOPLE, here is the solution for everyone that has this problem with Win 7 X64: (Thanks goes to Mikeztm for giving us info about the SHA256 thing)
- There is only one specific windows update required for the crimson 16.6.1 drivers to install on win 7 64bit and its Update KB3033929 x64. Here is a link: https://www.microsoft.com/en-us/download/details.aspx?id=46148
Just install this specific windows update and the crimsons drivers will install. (tested it out personally)
The reason why this happens is because the old SHA1 driver signature doesnt work anymore, so all hardware drivers from now on HAS to be SHA256 compatible BUT unpatched versions of windows 7 doesnt include the SHA256 authorization tool. So you have to install KB3033929 x64 to enable SHA256.
For the windows 10 insider guys this is more complicated because the SHA256 should have been compatible but it still doesnt work. AMD must fix this soon.