If you have a valid license key, but have lost the original media, you can still download the full versions of Office 2007 directly from Microsoft:

• Microsoft Office Enterprise 2007
• Microsoft Office Professional 2007
• Microsoft Office Small Business 2007
• Microsoft Office Home and Student 2007
• Microsoft Office Standard 2007
• Microsoft Office Accounting Professional 2007
• Microsoft Office Groove 2007
• Microsoft Office OneNote 2007
• Microsoft Office Publisher 2007
• Microsoft Office Visio Professional 2007