Microsoft small business knowledge base

Article ID: 2290554 - Last Review: June 21, 2014 - Revision: 39.0


When you type your product key during the installation of Office 2008 for Mac, you may receive the following error message:

Office for Mac has determined that your product key is not valid. To use Office for Mac, you must enter a valid product key.


 Method 1: Verify the correct product key is entered

To make sure that you are entering the correct product key, follow these steps:

1.  Verify that you are typing the product key and that you are not typing the CD-set number, the disc assembly number, or the part number.

The product key location is different based on what type of product you have purchased.  If you purchased boxed product, the Product key  is located inside the disc case or on the back of the disc sleeve on a rectangular orange label accompanying the installation media, that contains a 25-character product key.  

If you purchased the product by downloading it from Mactopia web site, the product key is located in your Order Confirmation email.

The number is displayed in the following format:


2.  Retype the product key. Make sure that you type it correctly.

Make sure that you type the correct characters. The following characters are frequently mistaken for one another:

• B and 8 
• G and 6 
• U and V 
• Q and O 
• The letter O and the numeral 0 (zero) 
• The letter L and the numeral 1 
3.  Verify that you are using the product key together with the correct product. Product keys work only for the product that the product key is assigned to. 
If you are entering the correct set of characters, and if you still receive the same error message, go to Method 2.

Method 2: How to obtain a replacement product key

For more information about how to obtain a new product key, click the following article number to view the article in the Microsoft Knowledge Base:

 2279109 Obtain a new product key for Office 2008  

Applies to
  • Microsoft Office 2008 for Mac
dftsdahomeportal KB2290554
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