I recently purchased Windows 8 Pro activation key for 40$. Now, this being a upgrade only license, it wont activate Windows 8 in the case of a clean install. As activation service in Windows 8 looks for any traces of the previous Microsoft OS on the system, when an upgrade only key is being used. In case of a clean install, it obviously fails to find any, hence it refuses to accept your key.
So the correct* way to successfully activate your Windows 8 with the upgrade key would be to first install/have Windows 7/Vista/XP on the computer and then insert your Windows 8 Pro DVD/USB and upgrade to Windows 8 Pro. I was installing Windows 8 on my new hard drive and didn’t have the time to install Windows 7 first. Here’s what I did to activate my Windows 8 with its genuine key in the case of a clean install.
*NOTE: Only follow these steps if you have a VALID Upgrade (I.e.: You legitimately own a licence for a previous version of Windows) Else, according to DRM, it would be considered a sort of piracy.
1. Do a clean install of Windows and during the installation, skip the step of entering the licence key, else simply enter your upgrade licence key.
Once you’re in Windows, you’re going to have to do some tweaking to “trick” it into letting you activate Windows with the Upgrade key.
2. Once you’re at your desktop, run Command Prompt as Administrator (Go to the start screen, type ‘cmd‘. You should see Command prompt on the list. Right-click it and click “Run as Administrator”. Click “Yes” on the Security Prompt).
3. At the command prompt, type: regedit and press Enter.
4. Once in Registry Editor, in the registry tree, navigate to this key:
5. In that folder, look for the item MediaBootInstall. Double-click it and change the value to 0
6. Close the Registry Editor. You should still have the Command Prompt open. Now, at the Command Prompt, type the following and press enter:
Note: The slmgr tool is discussed in detail at the end of the post.
7. It should show something that tells you the command was successful.
8. Restart the computer. Go to the Start Screen, type ‘activate’, click on the settings tab, click on ‘Windows
9. Enter your Upgrade product key and it should activate successfully!
Note: Here is a list of commonly used options along with the general syntax of the Software Licensing Management Tool (slmgr.vbs).[tabgroup]
slmgr [MachineName [Username Password]] [Option]
machinename The machine to administer, by default the current local machine.
username An administrator equivalent user account for the remote computer.
password The password for the user account on the remote computer.
/ato Activate Windows license and product key against Microsoft’s server.
/atp Confirmation_ID Activate Windows with user-provided Confirmation ID
/ckms Clear the name of KMS server used to default and port to default.
/cpky Clear product key from the registry (prevents disclosure attacks)
/dli Display the current license information with activation
status and partial product key.
/dlv Verbose, similar to -dli but with more information.
/dti Display Installation ID for offline activation
/ipk Key Enter a new product key supplied as xxxxx-xxxxx-xxxxx-xxxxx-xxxxx
/ilc License_file Install license
/rilc Re-install system license files
/rearm Reset the evaluation period/licensing status and activation state of the machine
Set the Volume Licensing KMS server and/or the port used for KMS activation
(where supported by your Windows edition)
/skhc Enable KMS host caching (default), this blocks the use of DNS priority and
weight after the initial discovery of a working KMS host.
If the system can no longer contact the working KMS host, discovery will be attempted again.
/ckhc Disable KMS host caching. This setting instructs the client to use DNS auto-discovery
each time it attempts KMS activation (recommended when using priority and weight)
Sets the interval in minutes for unactivated clients to attempt KMS connection.
The activation interval must be between 15 minutes and 30 days, although the default (2 hours)
The KMS client initially picks up this interval from the registry but switches to the KMS
setting after the first KMS response has been received.
Sets the renewal interval in minutes for activated clients to attempt KMS connection.
The renewal interval must be between 15 minutes and 30 days.
This option is set initially on both the KMS server and client sides.
The default is 10080 minutes (7 days).
/spri Set the KMS priority to normal (default).
/cpri Set the KMS priority to low.
Use this option to minimize contention from KMS in a co-hosted environment.
Note that this could lead to KMS starvation, depending on what other applications
or server roles are active. Use with care.
Sets the port on which the KMS host listens for client activation requests. The default TCP port is 1688.
/sdns Enable DNS publishing by the KMS host (default).
/cdns Disable DNS publishing by the KMS host.
/upk Uninstall current installed product key and return license status back to trial state.
/xpr Show the expiry date of current license (if not permanently activated)