In celebration of Windows 10's first birthday, Microsoft has rolled-out its biggest update to the love-it-or-hate-it operating system. However, Microsoft has made life a little harder for those who might find themselves regretting pressing the update button this time around as it has chosen to reduce the rollback period from 30 days to just 10.

The Anniversary Update (version 1607, OS build 14393.10) brings with it some major changes, most notably to its friendly personal assistant Cortana – which now cannot be switched off – and the introduction of Windows Ink to add extra functionality for stylus lovers.

Unfortunately, as with any significant update, there have been a few teething issues, bugs and reports of software incompatibility. Those frustrated with the changes will have to act quickly though, as Supersite Windows managed to spot a slight change in Microsoft's recovery options that now limits the rollback period to 10 days after the initial update.

In a statement to Supersite Windows, a Microsoft representative said:

"Based on our user research, we noticed most users who choose to go back to a previous version of Windows do it within the first several days. As such, we changed the setting to 10 days to free storage space used by previous copies."

With this in mind, if you are longing for the halcyon days of Windows 10 version 1511 and are still within the 10 day period, here's how to downgrade your OS (as always, you may want to backup any important data and documents before you continue):