Earlier in the year Microsoft announced that they are working with the Xiaomi user group to release a Windows 10 ROM for the Xiaomi E4 Android handset.
All Xiaomi devices come with unlocked ROMs, meaning users can easily load new versions of Android and even other operating systems. Xiaomi has given their blessing in sort to the venture, but are not officially backing it. this is obviously a Technical Preview version, presumably the same one that the Insider can install on existing Windows Phone. From June 1, the owners of Xiaomi E4 postranno download the ROM and install it on your Android terminal, converting it to done in a Windows 10 Mobile.
Now the user group has announced that the ROM will be available on the 1st June,
Check out the vedio