I’m a fan of MS Office 2007 now after getting use to it. One thing that is cumbersome though is, it saves files in a new format that previous versions of Office can’t open. This is frustrating working in a team environment, or sharing files with other people with older versions.
Here’s how you can change the default save method file type (.docx, .xlsx, etc) to save in the previous format for better compatibility:
For Excel, follow the same choices above except choose Excel 97-2003 Workbook (*.xls) in step 3.
Alternately, older versions of Office can download a compatibility pack that will allow you to open the new format: http://www.microsoft.com/downloads/