Foreign media Windows Latest reported that some users who installed the latest Windows 10 update (including KB4549951) reported that their user-profiles and all data, customization options, and documents were not loaded at login. After installing the update, Windows 10 will start and display a temporary user profile error bug, it may move your data or even delete them.
It seems that the problem still exists, and may affect more users. It is not clear why or how Windows 10 is loaded with a brand new user profile.
Many users also reported that after installing the Windows 10 KB4549951 patch released on April 14, the data including documents or pictures disappeared.
After installing the update, Windows renames the folder of normal user-profiles and then creates and loads temporary user profiles when the PC starts.
But the good news is that this error will not permanently delete most users’ profiles or data.
Original configuration files still are located in C:> Users in, but your data files to “.ooo” or “.bak” extension stored in.
Fortunately, there are many ways to recover it. If the Windows system is restarted 6 to 8 times, the user profile and data should be restored. But it may not work for everyone.
After updating from Windows 10 version 1903 to Windows 10 version 1909, some users also reported the problem.
According to the introduction of multiple Microsoft support staff, you can also solve the problem by setting up a new account and then manually transferring the data from the temporary account to the account.
A more consistent option is to only back up files stored on the system hard drive before installing the update. You need to always maintain a backup of data on the same partition as the operating system.