Microsoft’s giving you just 10 days to change your mind about Windows 10

Microsoft has hidden a new downgrade policy within the Windows 10 Anniversary Update: Once you’ve installed it, you’ll only have 10 days to downgrade to an earlier version or build, rather than the 31 days provided before.
Historically, Microsoft had given users a full month to roll back any updates, including upgrades to Windows 10. Supersite for Windows reported this week, however, that it was unable to downgrade to an earlier build after a 10-day limit had expired, though it