Why don’t I have the Get Windows 10 icon?

As always, from the Windows 10 FAQ:

Why don’t I have the Get Windows 10 app?

If you don’t see the Get Windows 10 app on your PC, it might be because:

1. Your device isn’t up-to-date with at least Windows 7 SP1 or Windows 8.1 Update.
2. Windows Update is turned off or is not set to received updates automatically.
3. You’ve blocked or uninstalled the necessary Windows Update functionality.
4. Your device is not running genuine Windows.

Running Windows Update and installing any available updates will fix the first three issues. Need more help? Go to our Windows Community Forum.

PCs that we determine cannot run Windows 10 will not see the Get Windows 10 app before July 29, 2015. After July 29, 2015, we’ll enable the icon in the system tray. This is to help ensure that you can easily check your PC’s compatibility if you choose.

If your device is managed as part of a school or business network, please check with your IT administrator about upgrading to Windows 10.

Additional info courtesy the answer to this MS Community question:

If you don’t think any of the conditions listed above apply to you and you’re still not seeing the icon, you can also try running the solution below which will verify that your device meets all the prerequisites and will then turn on the Get Windows 10 app:

1. Copy the following text and paste it into Notepad:

   REG QUERY "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\UpgradeExperienceIndicators" /v UpgEx | findstr UpgEx
   if "%errorlevel%" == "0" GOTO RunGWX
   reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Appraiser" /v UtcOnetimeSend /t REG_DWORD /d 1 /f
   schtasks /run /TN "\Microsoft\Windows\Application Experience\Microsoft Compatibility Appraiser"
   :CompatCheckRunning
   schtasks /query /TN "\Microsoft\Windows\Application Experience\Microsoft Compatibility Appraiser"
   schtasks /query /TN "\Microsoft\Windows\Application Experience\Microsoft Compatibility Appraiser" | findstr Ready
   if NOT "%errorlevel%" == "0" ping localhost >nul &goto :CompatCheckRunning
   :RunGWX
   schtasks /run /TN "\Microsoft\Windows\Setup\gwx\refreshgwxconfig"
   

2. Save the file as "ReserveWin10.cmd" (with the quotes, name can be anything).

3. Open an elevated (admin) command prompt and run the file from the location you saved it to. For example:

   C:\Temp\ReserveWin10.cmd
   

The script will run until it has an answer.

From http://answers.microsoft.com

The Microsoft Compatibility Appraiser can take 10 – 30 minutes to run, during which the script will continuously provide status reports that it is running. Please be patient.

If the script is failing in an infinite loop, then you don’t have the necessary prerequisite Windows Updates. Besides requiring Windows 7 SP1 or Windows 8.1 Update, you must also have installed:

For Windows 7 SP1:

KB3035583

KB2952664

For Windows 8.1 Update:

KB3035583

KB2976978

Important note and explanations about the script in the other answer.

This script force-launches the 2 sets of scheduled tasks generated by the KB2952664/KB2976978 and KB3035583.

The first set of tasks is running the compatibility appraiser, to determine if your computer can handle Windows 10 according to some criteria (in which case it shows you the icon prior to the 29th). This task does take between 10 and 30 minutes. After that, the second set of tasks (linked to the KB3035583) can be launched, to actually display the icon.

The script above does not really print a friendly message while waiting. All it does is check the status of the force-launched scheduled task, until it comes back from "Running" to "Ready". As such, it can look like the infinite loop they are talking about, but it's not, as long as you don't see that it "failed" somehow. You just have to let it run its course.

For the record, on a computer which had its automatic updates running, or was kept up to date manually, this script has no reason to be required. Indeed, the first required update was available in April 2015, and it registered some scheduled tasks to run this compatibility appraisal. So in this situation, chances are that it ran prior to having KB3035583 installed on your computer.

KB3035583 also adds a set of scheduled tasks (checking at 20:00, if I remember well), so that's why its action is not instant either.

This whole process of showing the icon was meant as a background task, not something jumping as soon as you install it. This is why people rushing all the updates on their system in one day (like myself) don't get the icon instantly. And this is why there is such script, to jumpstart the process, but it's important to let it run its course.

Microsoft published 2 KB articles:

The "Get Windows 10" app doesn’t appear in Windows 7 or 8.1
https://support2.microsoft.com/kb/3081048/en-us

Here 2 possible causes why the icon is missing:

1. If your device is or has been connected to a domain, or is managed by a system administrator, it may be blocked from the upgrade reservation. Check with your IT administrator.
   
2. If your copy of Windows is not genuine, or if you have a Volume License copy (intended for businesses), the icon will not appear. To check this, open a Command Prompt (from the Start menu or screen, search for cmd, right-click on Command Prompt in the results and select Run as administrator), type slmgr /dli and then hit Enter. A window will appear with the channel in the Description line (Retail, OEM, or Volume), and the License Status. If your copy of Windows is not activated, refer to Knowledge Base article 950929 for more information. If you have a Volume License copy, it does not qualify for the free upgrade.

How to manage Windows 10 notifications and upgrade options
https://support2.microsoft.com/kb/3080541/en-us