Which files will be lost after upgrading the official version of Windows 10

What can I keep when I upgrade to Windows 10?
Microsoft pointed out that the files that can be retained by different system upgrades to Win10 Technology Preview are also different.
Windows 8.1 or Windows 8 preserves Windows settings, personal files, and most applications when upgrading Windows 10 Technology Preview.
Windows 7 upgrades also preserve Windows settings, personal files, and most applications.
Vista can't keep anything, you have to boot from the media and perform a fresh install.
Windows RT 8.1 or Windows RT cannot be upgraded to Windows 10 Technology Preview.

Note:
If you are running Windows 8.1, Windows 8, or Windows 7, but the system language is not English, Chinese (Simplified) or Portuguese (Brazil), you can only keep individuals during the upgrade. File, cannot retain application or Windows settings.
If your Windows 8.1, Windows 8, or Windows 7 has Language Pack or Language Interface Pack (LIP) installed, they will be automatically removed when you install Technology Preview.