Not able to download minecraft windows 10 beta

Hello,

I can't download the windows 10 edition and i don't understand it.
I just include some screenshots because i don't know why i can't download it.
I've checked processor and everything should be OK.
I got my gift code.
For the first capture, i can't even buy it !
For the "dt"-named capture, this is what the system require
And the "system"-named capture is my system's informations
I'm sorry these capture are in french and i could not translate them with my poor English, very sorry about that :/
Thank you for answering.