When you install or reinstall a Microsoft Office system program, you are prompted to type or paste the 25-character product key. The product key is used during Microsoft software installation to "unlock" or to open the product. If you do not enter the product key when you are prompted during the installation, the product may not open.

Important If you cannot find the product key for your trial version, you have to purchase a full version. When you are converting from a trial version to a full version of Microsoft Office, you must use the product key from the full version to convert it.

This article describes how to find the product key if you cannot locate it, or how to obtain a new product key if the product key label is damaged or is missing. If the product key label is damaged or missing and you have to replace the product key, go to the "How to replace a damaged or lost product key for a full version" section. If you have your product key and it is not working, contact Support at the following Microsoft Web site:

Product key information

The process to find or replace a product key is different for a trial version than it is for a full version of the product. A trial version is a free, temporary version of a Microsoft product that lets you activate one time to try it before you purchase it. After you activate the trial version, it is fully functional for 60 days. To find the product key for a trial version, go to the "How to locate the product key for a trial version" section.

A full version is licensed. This means that you can activate the software two times, on two computers for example, and use the software for the life of each computer. To find or replace the product key for a full version, go to the "How to locate the product key for a full version" section.

How to check whether you have a trial version or full version of the product

If you are not sure whether you have a trial version or full version, you can check by using the installation CD. If you do not have your installation CD, go to the "How to locate the product key for a trial version" section or the "Next steps" section for information about how to contact Support.

To check your version using the installation CD, follow these steps:

1. Insert your Office XP CD-ROM into your CD or DVD drive.
2. Click Start, click All Programs, and then under Accessories, click Windows Explorer.
3. In the left navigation pane under My Computer, click the CD or DVD drive icon in Windows Explorer to view the files.
4. In the right navigation pane, locate the .msi file.

If your installation is a trial version, the .msi file name has "tri" appended to it (for example, Protri.msi). A full version has "ret" appended to the .msi file name (for example, Proret.msi). A full version of Windows XP Enterprise does not contain "ret" or "tri" in the file name, for example, Pro.msi or Proplus.msi.

How to locate the product key for a trial version

Important You can run a trial version of a Microsoft Office system program up to 25 times before you must enter a product key. After this grace period, if you have not entered a valid product key, the software goes into Reduced Functionality mode and many features become unavailable. Although it is not required, we recommend that you enter your product key at installation.

Note If you are converting from a trial version to a full version of Microsoft Office, you must use the product key from the full version of the 2007 Microsoft Office system. For information about where you can find the product key for a full version, go to the "How to locate the product key for a full version" section.

You may be able to find the product key for a trial version in more than one location, depending on how it was obtained (CD/DVD, downloaded, subscription, or preinstalled by the computer manufacturer, system builder, or reseller). To find the product key for a trial version, check the following locations:

• Desktop Trial icon when a preinstalled trial is available.
• Sticker on CD case or other packaging.
• Microsoft Product Identifier Card.
• Confirmation e-mail message that was received from an online download or renewal notice.

If you still cannot find the product key for your trial version, unfortunately, the product key cannot be replaced and you will have to obtain a full version of the 2007 Microsoft Office system, for more information, visit the following Microsoft Web site:

How to locate the product key for a full version

You may be able to find the product key for a full version in more than one location, depending on how it was obtained (CD/DVD, downloaded, subscription, or preinstalled by the computer manufacturer, system builder, or reseller). To find the product key for a full version, check the following locations:

• Sticker on the CD case or other packaging.
• Certificate of Authenticity.
• Confirmation e-mail message that was received from an online purchase.
• Sticker on the computer.
• Documentation or user manual included with your computer.

If you still cannot find the product key for your full version, go to the "How to replace a damaged or lost product key for a full version" section.

How to replace a damaged or lost product key for a full version

If you cannot find your product key, you can obtain a new one. To obtain a new product key, contact Support. Find the Support telephone number for your area by running the Product Activation Wizard on your computer. For more information about how to run the Product Activation Wizard, click the following article number to view the article in the Microsoft Knowledge Base: When you contact Microsoft for a new Office product key, please have the following items available for the customer service representative:

• The product CD-ROM.
• The computer on which you want to install Office.
• The readable parts of your original product key (if available).
• The ProductID information in the registry (for advanced users only).

For more assistance, go to the "Next Steps" section for information about how to contact Support.

If these methods did not help you, you might want to ask someone you know for help, or, you can also use the Microsoft Customer Support Services Web site to find other solutions. Some services that the Microsoft Customer Support Services Web site provides include the following:

• Searchable Knowledge Base (http://support.microsoft.com/search/?adv=1) : Search technical support information and self-help tools for Microsoft products.
• Solution Centers (http://support.microsoft.com/select/?target=hub) : View product-specific frequently asked questions and support highlights.
• Microsoft Customer Support Newsgroups (http://www.microsoft.com/communities/newsgroups/default.mspx) : Contact counterparts, peers, and Microsoft Most Valuable Professionals (MVPs).
• Other Support Options (http://support.microsoft.com/default.aspx?pr=csshome) : Use the Web to ask a question, contact Microsoft Customer Support Services, or provide feedback.

If you continue to have questions after you use these Microsoft Web sites or if you cannot find a solution on the Microsoft Support Services Web site, click the following link to contact Support: