If you would like to open, edit, and save documents, workbooks, and presentations that were created in Word, Excel, and PowerPoint 2007 or 2010, you have to install the compatibility pack designed for 2003/XP/2000 users.
The pack is designed by Microsoft, and you can free download it (multiple languages) at Microsoft web site.

Why don't you want to upgrade to Microsoft Office 2007 and 2010? Because of the new ribbon inteface? Do you get used to the old menus and toolbars? If yes, please scroll down to see instructions.

If you like new functions of Office 2010 but don't like the new ribbon interface, the free replacement of Office Compatibility Pack - Classic Menu for Office 2010 is the best choice. It is fully free (personal and non-commercial use).
The software brings the familiar interface - classic menus and toolbars to Microsoft Office 2010, includes the main menu, standard toolbar and formatting toolbar. Just like working with Office 2003, Office XP and Office 2010.
You don't need any trainings and tutorials for Office 2010 after upgrading.

• ToolbarToggle Lite 2.0.0.10
  ToolbarToggle is great for new users transitioning to Office 2007 and 2010 or for power users who want the freedom to use both the Ribbon and the toolbar together. ToolbarToggle...

• Classic Menu for Office Professional Plus 2010 3.50
  

  Show Classic Menus and Toolbars on Ribbon of Microsoft Office Professional Plus 2010, and brings back the classic view and old interface to Office Professional Plus 2010

• Classic Menu for Office Professional Plus 2010 64 Bit 3.50
  

  Show Classic Menus and Toolbars on Ribbon of Microsoft Office Professional Plus 2010 64-bit, and brings back the classic view and old interface to Office Professional Plus 2010 64-bit. Where are the Office 2010 toolbars? You could not find the...

• Classic Menu for Office Enterprise 2010 3.01
  If you have spent a lot of time adjusting yourself to the Ribbon interface of Microsoft Office 2010, or being frustrated by searches for new features on the Ribbon interface, Classic Menu for Office Enterprise 2010 will help to solve your problem

• Classic Menu for Office Professional 2010 3.01
  If you have spent a lot of time adjusting yourself to the Ribbon interface of Microsoft Office Professional 2010, or being frustrated by searches for new features on the Ribbon interface, Classic Menu for Office Professional 2010 will help to solve your problem. The software adds a Menus tab to the whole interface of Office Professional 2010,...

• Classic Menu and Toolbar for Microsoft Office 2010 4.50
  Frustrated by endless searches for features on the Ribbon? You can use Office 2010 immediately without any training or tutorials if you used Office 2003 before

• Classic Menu for Office Home and Business 2010 3.01
  If you have spent a lot of time adjusting yourself to the Ribbon interface of Microsoft Office Home and Business 2010, or being frustrated by searches for new features on the Ribbon interface, Classic Menu for Office Home and Business 2010 will help...

• Classic Menu for Office Standard 2010 3.01
  If you have spent a lot of time adjusting yourself to the Ribbon interface of Microsoft Office Standard 2010, or being frustrated by searches for new features on the Ribbon interface, Classic Menu for Office Standard 2010 will help to solve your problem

• Classic Menu for Office 2010 Starter 32bit 2.0
  The software is free for personal use. It brings back the familiar Office 2003 and 2007 toolbars and menus into your new ribbon interface of Microsoft Office 2010. It only...