The directions are a little intricate and they must be followed precisely.
Double check your work. I used this fix using Outlook Express and Windows XP
and the problem was resolved. Don't forget to restart your computer after
it's done.

What was formerly grayed out in Word 2007 with regard to "Send as e-mail
attachment" was then enabled and completely functional.

Hope this helps.

Can you provide the exact wording of the error, and any files that are
mentioned in the error message? (You might also go into the Windows Event
Viewer immediately following a crash to get the details of exactly what
module is causing the crash.)

I'm assuming that you've already tried doing a repair (Control Panel -
Add/Remove Programs - Office 2007 - Change - Repair). If not, then give it a
try.

If repairing doesn't fix it, do you still get the problem if you start Word
using the /a switch (winword.exe /a) ?

If not, then there probably is a corrupted registry entry or a corrupted
template that is causing the problem. The steps described here usually help
in troubleshooting and finding a permanent solution:

http://word.mvps.org/FAQS/AppErrors/ProbsOpeningWord.htm

If that doesn't result in a fix, the next thing I would try would be to
create a new Windows User profile, and see if the new user has the same
problem.