What software files might be lost following upgrading Windows 10: What content could be kept right after upgrading to Windows 10 version? Microsoft pointed out that
http://www.luckyrecovery.com/howto/recover_1292_3241_1_0_0_0_0_0_0_0_0_de_0_0_0_list.html that may be retained when upgrading to Win10 Technologies Preview for unique systems are also diverse.
Windows eight.1 or Windows 8 can retain Windows settings, private files, and most applications when upgrading Windows ten Technologies Preview.
sd card can also retain Windows settings, personal files and most applications when upgrading.
Vista cannot retain any content and should boot in the media and perform a clean installation.
WindowsRT8.1 or WindowsRT cannot be upgraded to Windows10 Technology Preview.
note:
For anyone who is operating Windows8.1, Windows8, or Windows7, but the technique language is just not English, Chinese (Simplified), or Portuguese (Brazil), you can only preserve personal files when upgrading, not apps or Windows settings.
In case your Windows 8.1, Windows eight or Windows 7 have installed language packs or language interface packs (LIP), they may be automatically deleted when installing the technologies preview.