To activate by phone, click on Start and type slui.exe 4 followed by Enter in the Search/Run box.
This is not Microsoft. It is a user to user forum hosted on Microsoft servers for the convenience of its users. To get a phone number for support start here
http://support.microsoft.com/kb/319726
If you want help from this forum simply give your computer's make and model, the edition of Windows you are trying to activate, where you are getting the product number you are attempting to activate, and any error message you see.
Colin Barnhorst Windows 7 Ultimate x64 on DIY with 6GB ram.