
Again, this can be prevented using Windows 10 Upgrade Companion, as you can see in the tutorial below.

current Windows is Home, upgrading to Windows 10 Pro), your programs and files will also be removed. In addition, if you are upgrading from a 32bit Windows to a 64bit Windows 10, or upgrading to a different edition (i.e. This can be prevented using Windows 10 Upgrade Companion – a special tool that preserves your programs, settings and files through the upgrade. If you are currently using Windows XP, Windows Vista, Windows 7 SP0 or Windows 8 (not 8.1), then Windows 10 upgrade will erase all your program and files (see Microsoft Windows 10 Specifications).

NOTE on preserving your programs and files:

In this article, we’ll learn how to upgrade to the new Windows 10 from XP, Vista, Windows 7 and Windows 8/8.1, while making sure no programs or files are lost in the process. Windows 10 is officially released on July 29th, 2015.
