Microsoft released Office 2007 to retail customers early this year. Many are thinking about upgrading from a previous version of Office.

In general, it isn't necessary to upgrade with each release. Microsoft doesn't usually make major changes. Mostly, it gets a few new features and a freshened look.

But Office 2007 is different. Yes, Microsoft has made significant changes to the menus and toolbars. But the suite also uses completely different file structures. This pretty much forces you to upgrade. That is, if you share documents with others.

If you receive an Office 2007 document, you won't be able to open it in Office 2003. Currently, though, Microsoft is offering an Office Compatibility Pack for some Office applications. It allows you to work with Office 2007 files in Office 2000, XP and 2003.

I wouldn't rely on the Compatibility Pack. Some features won't be available. And I'll bet there's the potential for garbled documents.

The new version of Office is confusing at first. But the programs are prettier than the current version. And new users will probably find them fairly intuitive.