excerpt from: http://www.itbusiness.ca/it/client/en/home/News.asp?id=50023
Microsoft Office 2007's XML file formats can complicate migration and file sharing; be prepared. Also, tweak the suite's ribbon interface.
Even if you don't plan to switch from your current Office apps, you'll have to deal with Microsoft's 2007 Office System because the people using it may be sending you files in the upgrade's XML file formats.
And if your company is rolling out Office 2007, you'll have to migrate your beloved settings and files from Office 2003, which can be easy, difficult, or impossible (some of your favourites may have been eliminated).
Prep Your 2003 Apps
Regulars at Microsoft's update site have probably already downloaded and installed the company's Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats.
The pack lets people using older Office versions open, work on, and save files in the 2007 Office System's native XML formats: .docx for Word, .xlsx for Excel, and .pptx for PowerPoint. Browse to the Microsoft Download Center to download and install the compatibility pack manually. (Downloading the 27MB file may take several minutes.)
Make the Switch to 2007
Before you upgrade, back up your data, including your custom templates, forms, and macros. Then insert your Office 2007 disc; and at the 'Installation You Want' screen choose Upgrade earlier versions. Select Remove all previous versions if you want to delete your 2003 apps while retaining some of your settings, such as Word's custom dictionaries, Excel's custom lists, and Outlook's .pst file.
If you click Keep all previous versions, you'll do just that, Outlook excepted; you can have only one version of that program on your system.
To keep Outlook 2003, click the Installation Options tab and set Microsoft Office Outlook to Not Available. To install Outlook 2007 in place of Outlook 2003, select Remove only the following applications and check just the Microsoft Office Outlook box.
more about Outlook migration
