Microsoft offers free Office 2010 upgrade if you buy Office 2007 starting March 5th, 2010.

Microsoft is offering free Office 2010 upgrade for every Office 2007 purchased between March 5th and September 30, 2010.

From Amazon:

Promotion Details

  1. Buy a qualifying Office 2007 product (with or without a new PC) between March 5 and September 30, 2010.
  2. Install and activate your qualifying Office 2007 product by September 30, 2010. This qualifies you to upgrade to the corresponding Office 2010 product.
  3. Once the corresponding Office 2010 is available, simply go to www.office.com/techg by October 31, 2010 to download it at no additional cost, or purchase a DVD for a fee. Follow the online steps to verify eligibility. You will need an activated Office 2007 Product Key.
  4. Download the product and receive an Office 2010 Product Key online. There is an option to purchase a DVD for a fee.

* Office 2010 downloads will be accessible at general availability. Discs can be ordered for a fee. Eligible Office 2007 software must be purchased from Microsoft or an authorized reseller and activated between March 5, 2010 and September 30, 2010. Request your Office 2010 product by October 31, 2010 using your activated Office 2007 Product Key and dated sales receipt. One (1) Office 2010 product per qualifying Office 2007 purchase, limit 25 per person. For complete details, visit www.office.com/techg.

From Microsoft (FAQ):

Below are some of the Office 2007 products that qualify for the Technology Guarantee.

  • Office Home and Student 2007
  • Office Small Business 2007
  • Office Professional 2007
  • Office Publisher 2007

See full list of Office 2007 qualifying products.

Remember, according to Microsoft Licensing you must not use Office 2007 once you upgraded to Office 2010. I guess they can enforce that by deactivating your Office 2007 installation.