Can I use clip art in a book I'd like to publish?

That's an interesting question. The use of the clip art is governed by
the End User License Agreement (EULA), to which you agreed when you
installed Office. You can read it again by clicking Help About
Microsoft Word and clicking the link in the dialog.

This appears to be the appropriate section from the Office 2003 EULA
(but read the whole thing yourself):

-------------------
1.5 License Grant for Media Elements. The Software may include
certain photographs, clip art, shapes, animations, sounds, music and
video clips that are identified in the Software for your use (together
"Media Elements"). You may copy and modify the Media Elements, and
license, display and distribute them, along with your modifications as
part of your software products and services, including your web sites,
but you are not licensed to do any of the following:
• You may not sell, license or distribute copies of the Media
Elements by themselves or as part of any collection, product or
service if the primary value of the product or service is in the Media
Elements.
• You may not grant customers of your product or service any
rights to license or distribute the Media Elements.
• You may not license or distribute any of the Media Elements
that include representations of identifiable individuals, governments,
logos, initials, emblems, trademarks, or entities for any commercial
purposes or to express or imply any endorsement or association with
any product, service, entity, or activity.
• You may not create obscene or scandalous works, as defined by
federal law at the time the work is created, using the Media Elements.

In addition, you must (a) indemnify and defend Microsoft from and
against any claims or lawsuits, including attorneys' fees that arise
from or result from the licensing, use or distribution of Media
Elements as modified by you, and (b) include a valid copyright notice
on your products and services that include the Media Elements.
-------------------

With the disclaimer that I'm not an attorney (and you may want to
consult one), I'll give my opinion that this language does permit you
to use the clip art in a published book, provided you include a "valid
copyright notice" -- however that's defined -- and it's neither a book
of just clip art nor "obscene or scandalous". The other provisions are
easy to meet.

--
Regards,
Jay Freedman
Microsoft Word MVP FAQ: http://word.mvps.org
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