I dont now how activate the window 7 - Computers & Internet

You can activate your Windows 7 online.
1. Go to <Control Panel>\<System and Security>\<System>
2. On lower part of the window you can see the days remaining.
3. If you can see like: Activate or Activate Windows? Click that link. And it will automatically send the an information to Microsoft and verify if the copy of your Windows 7 OS is genuine.

Make sure you are connected to the internet and then click on the windows activation icon and follow the onscreen prompts and windows will activate, if it doesnt activate online then you either have a pirate copy of windows or your copy has been flagged as counterfeit, in that case you will need to choose activate by telephone then ring the free phone number shown for your country and follow the automated steps given on the phone

Windows 7 should activate via an internet connection within 30 days. If not when it promts you for activation options choose phone activation and follow the prompts.

Click the Start button (Orb in the lower left hand corner of the screen). RIGHT click on Computer and select Properties from the menu. At the bottom of the window you will see the Windows Activation section and an option to Activate Windows Now. Click on it and the activation dialog screen will appear.