The Windows 10 site displays a tiny disclaimer giving more details about the upgrade.
It is our intent that most of these devices will qualify, but some hardware/software requirements apply and feature availability may vary by device. Devices must be connected to the internet and have Windows Update enabled. ISP fees may apply. Windows 7 SP1 and Windows 8.1 Update required. Some editions are excluded: Windows 7 Enterprise, Windows 8/8.1 Enterprise, and Windows RT/RT 8.1. Active Software Assurance customers in volume licensing have the benefit to upgrade to Windows 10 Enterprise outside of this offer. We will be sharing more information and additional offer terms in coming months.
This means the following:
- The upgrade will be done via Windows Update
- Windows 8 customers need to *somehow* upgrade to Windows 8.1 ( getting past those store upgrade issues)
- Enterprise versions are excluded. (This is not a problem since most will have a MSDN or volume license)
- The most important Windows RT and Windows RT 8.1 are excluded.
- No Windows 10 free upgrade for Surface RT and Surface 2 customers. (They could buy Windows 10 for ARM, if it is announced)
- Paul Thurrott: Windows 10
- Rollup: Microsoft HoloLens, Surface Hub, Windows 10, Xbox One game streaming and more