I have been encountering a number of these lately, a person with a laptop wants to reinstall Windows 7, something goes wrong, either their recovery partition is damaged or they don’t have any recovery disc. Thankfully, all machines that ship with Windows 7 come with a genuine proof of license, the COA sticker, located sometimes at the bottom of a laptop or in the battery compartment (if you are using a desktop computer you can look at the side or top. What this means is, you can reinstall Windows 7, using the corresponding edition Windows 7 retail disc and use the product key located on the COA sticker to reactivate it.
For example, if you bought a laptop that came with Windows 7 Home Premium OEM and you would like to reinstall Windows 7 but have not way of doing so, you can use a retail disc, whether it be a full or upgrade version Windows 7 Home Premium disc.
Once you have installed it, all you need to do is change the product key located on the Certificate of Authenticity (COA). Lets take a look at how to do that.
Click Start, right click Computer
Scroll down to Windows activation.
You will notice it displays a time until Activation but be completed. Also the Product ID indicates it is using a default key, this is only for the 30 day grace period allowed until you must activate Windows 7.
Click the link, Change product key
Enter the product key located on the COA sticker located at the bottom or (sometimes in the battery compartment of your laptop), you can also find it at the top or side if its a Desktop computer. It looks something like the following:
Proceed to enter the product key and click Next
Wait while Windows attempts to activate.
If all goes well, within a minute, you should see this screen.
You can further confirm Windows 7 is activated by checking the Windows Activation status:
Notice Windows 7 now displays OEM within the Product ID to indicate the product channel it is licensed from. Please note, this also works with Windows Vista if you are still running that version.
If you are unable to activate Windows 7 using the Change product key method, you can try phone activation and speak with a call agent who will assist with reactivating Windows 7:
How to activate Windows 7 manually (activate by phone)
1) Click Start, and in the Search box type: slui.exe 4
2) Next press the ‘ENTER’ key
3) Select your ‘Country’ from the list.
4) Choose the ‘Phone Activation’ option.
5) Stay on the phone (do not select/press any options) and wait for a person to help you with activation.
6) Explain your problem clearly to the support person.
COA Certificate of Authenticity:
What is the Windows Certificate of Authenticity?