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How to replace a lost or damaged Microsoft Office product key
Explains what to do if you need a new product key for installing Office applications when your key label is damaged or is missing.
Invalid product key errors in Microsoft Office
Provides a solution to help resolve this validation error in Microsoft Office 2010: "This is not a valid Office Product key."
Video: Install and activate the Analysis ToolPak and Solver - Office.com
Learn how to install and activate the Analysis ToolPak and Solver add-ins so that you can use these powerful data analysis tools.
Microsoft Office Activation/Registration Privacy Statement - Excel - Office.com
Office 2003 activation and registeration privacy notice
Activate Office 2010 programs - Excel - Office.com
To activate an Office 2010 program, you must enter your 25-digit product key, if you haven't already done so during Setup.