Why can't people read my Office 2007 attachments?

I have recently installed Microsoft Office 2007 on Windows XP. I can now open any attachment sent to me. However, no one can open attachments sent by me. June Mould

Office 2007 defaults to using the new and much improved Office Open XML file formats, such as docx, rather than the ones used for the past decade.

However, you can still use the old formats. If you click the round Office button in the top left and mouseover Save As, you can then click the appropriate entry on the right pane. In Word, for example, it says: "Word 97-2003 Document". If you click Save As instead, you'll get a Save box where you can select from a couple of dozen options including Web page and WordPerfect. Rich Text Format (rtf) is usually a good choice, unless your document includes images.

But people are using the new formats, so you should also tell your friends to download the Compatibility Pack for Microsoft Office 2000, Office XP, and Office 2003. This will enable them to read and write OOXML without buying Office 2007. Apple's Leopard operating system also supports the new formats, while iWork 08 and the iPhone can read them