Office is not an operating system.
It's a collection of tools assembled by Microsoft for use in an office, e.g. Microsoft Word for word processing, Microsoft Excel for spreadsheets, Microsoft Access for databases.
You're probably thinking of "Microsoft Office" not "Windows Office", because no such thing exists.
However, if you're thinking of "Windows 2000" (Professional Edition), then that is an operating system. And I would fully recommend it 100% as it looks just like ME, but is about 100billion times better.
Master of common sense. If you don't like it, stop reading.