What is involved in migrating from earlier versions of Windows to the Windows 10 Technical Preview for Enterprise?

You can migrate volume licensed computers, managed using System Center Configuration Manager software distribution or Group Policy, to Technical Preview using the in-place upgrade process. For more information, see Try it out: Windows 10 Technical Preview for Enterprise. Here are some things to consider:

• If you're running Windows 8.1, Windows 8, or Windows 7 and your system language isn't English, Chinese (Simplified), or Portuguese (Brazil), you can only keep your personal files when you upgrade. You won't be able to keep your apps or Windows settings.
• If you're running Windows 8.1, Windows 8, or Windows 7 and have installed a language pack or a language interface pack (LIP), they'll be removed when you install Technical Preview.