Try this page, it might help:

http://support.microsoft.com/kb/2662392#Method3

 

Maybe you've turned off spell check as you type.

Look under the round office button on the top left, click the "word options" button, then select "proofing". There's a "check spelling as you type" option that can be turned off.

 

I'm just jumping on this thread to pimp Scrivener.  I love it so much I want everyone to use it.  It has a spell check feature too. 

 

Awesome answers. Thanks guys. Knew you could help me.

 

I agree with Elle.

Dara you should be using Scrivener 

It's the best software for authors I have ever seen, and I've tried them all (or barely all).

Everything on a single project, research, pictures, notes, the actual manuscript, etc.

No pressure, but try the demo (if you do you'll hate Word). And if you have a Mac, even better, the Mac version is cooler (not many differences but enough).

 

Congratulations! You have finally achieved perfection in your writing.

Tee hee. I guess you're right. My manuscript must be perfect.

Elle and PJ, thanks for the recommendation of Scrivener. I'll check it out.

 

You may have already gotten this solved by Annette's link, but just wanted to chime in to say that at one time, if I ran spell-check on my document, I'd get "no errors found."  And this was a 40,000-word document with unusual name spellings, and characters who say "ain't" or "who'da thunk?" etc.  I wasn't sure what was going on, but I realized I'd had Word, and the document, open for days while I worked on the ms, so I saved it and closed Word.  When I went back to it a few hours later it was fine and spell-check was working normally.  (But I use the 2010 version, so ymmv.)

In any case, I hope you got it straightened out.  I know I've accidentally turned features on and off and it can be a pain until you figure it out!)