How to open a new login interface for win10 9926 preview?

After installing the latest version of Windows9 9926, some people's system login interface has been changed from a square avatar of the original Windows 8/8.1 login interface to a round avatar, but some people's avatars stay at windows8.1. The state, then my method will let everyone freely change between the two.

1, press Windows+R to open the run, then type regedit and press Enter to open the registry editor

2. Locate the following location: HKEY_LOCAL_MACHINESOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Authentication\\LogonUI\\TestHooks

3. Find and double-click "Threshold" in the list on the right, and change the key value to 1 in the pop-up window. (1 is the new version of the rounded corners, 0 is the old version of the square corner

4, exit the registry editor

5, the final effect