The second major update to Windows 10, version 1607, was officially released two weeks ago, on August 2. So why haven't the PCs in your home and office received the Anniversary Update yet?
With an installed base of nearly 400 million devices, that rollout is going to take a while.
You can accelerate the process if you'd rather not wait. There are also ways you can defer the upgrade if you would rather watch and wait as other people shake out the inevitable bugs.
And if you're an IT pro in charge of deploying Windows 10, you have a whole different set of tools at your disposal.
Here are your options.
Waiting for Windows Update
As was the case with the two previous Windows 10 releases, Microsoft is "throttling" delivery of this upgrade through Windows Update. Devices that will receive it first are those that should, in theory, be best equipped to deal with it.
There's no official word on how long it will take for the full population of Windows 10 PCs to receive the update, but if past performance is any indication it could take two months or more. You won't receive any advance notice that the update is available; once it's ready to install, Windows Update will schedule a restart time.
In my experience, the update takes between 45 and 90 minutes, depending on your resources. You can schedule an installation time up to five days in the future, but you can't postpone it indefinitely.
Accelerating the update
The trouble with waiting, of course, is that you risk having the update arrive at an inconvenient time - as you're scrambling to leave for a business trip, for example.
In that case, your best option is to manually initiate the update. You can do that by going to the Windows 10 download page and clicking the big Update Now button.
That button runs the Windows 10 Upgrade Assistant, which downloads the installation files in the background and then allows you to schedule the upgrade.
Note that on some PCs with minimal resources, the Upgrade Assistant won't work. That's the case with HP's Stream 11, for example, which doesn't have enough free storage for the upgrade to succeed. On devices like that, the workaround is to use the Media Creation Tool (also available from the Windows 10 download page) to kick off the upgrade.
Delaying the update
If you're not ready for the Anniversary Update and you are running Windows 10 Pro, Enterprise, or Education editions, you can defer the upgrade, using the instructions I published here: Windows 10 tip: Temporarily delay the Anniversary Update
Making this change in Group Policy moves your PC from the Current Branch to the Current Branch for Business. You'll continue to receive security updates for your installed edition, but you will not receive version 1607 via Windows Update until it's released to the Current Branch for Business (CBB), at least four months after the Current Branch release on August 2.
That should mean that version 1607 will be ready for the CBB in the November/December timeframe.
Using other options in the same Group Policy setting, you can defer that upgrade by an additional period of up to eight months.
If you're running Windows 10 Home, there are no supported ways to stop the Anniversary Update.
Using deployment tools
If you're an IT pro with Microsoft deployment tools at your fingertips, you can take control of the process the way you traditionally have.
The installation bits for Windows 10 version 1607 should appear on Windows Server Update Services (WSUS) today. You still need to approve the feature update package before it's deployed. Devices on your network will receive version 1607 as soon as you approve it, unless you've configured them to defer upgrades.
If your organization uses System Center Configuration Manager, you also need the installation bits from WSUS. Your servicing plans will determine when the package is deployed.
For organizations with Windows 10 Enterprise licenses, you can download the installation media from the Volume Licensing Service Center and use Configuration Manager task sequences to deploy it.