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Here's the fix for the broken spell checker in Word 2007 after upgrading from 2003.

http://mcpmag.com/articles/2007/03/27/putting-a-spell-on-word-2007.aspx

Putting a Spell on Word 2007

Word 2007's spelling checker not working after you've upgraded? Here's a fix.

By Chris Wolf 3/27/2007

Chris: I just upgraded three systems to Office 2007 from Office 2003 and on two of them, the spelling checker in Word 2007 no longer works. I tried a few Google searches, but found nothing that would solve my problem. Any help is appreciated.
--Jim

Many of us in IT have disabled the spelling checker feature of our brain and let the Office speller take over, thus freeing our minds to wander a little more as we type. Unfortunately for me, my spelling skills peaked way too early in life. I won the school spelling bee in the fourth grade and it was all downhill from there. Today, I can't imagine life without the Office 2007 spelling checker, so Jim, I definitely feel your pain.

After polling some colleagues and performing a few tests on my own systems, I was able to duplicate Jim's problem. Following Jim's attempted resolution, I also tried to rerun Office 2007 setup to repair the installation, which, like Jim's experience, did not solve the problem. I next examined the Proofing Tools portion of the Windows registry on a known good and a known bad system. The Proofing Tools information in the Windows registry is located in "HKEY_CURRENT_USER\Software\Microsoft\
Shared Tools\Proofing Tools\1.0." On the system whose spelling checker did not work, there existed a subkey named "Override" within the "1.0" key. The known good systems did not have an "Override" subkey.

After digging a little deeper, I noticed that the two REG_SZ values in the "HKEY_CURRENT_USER\Software\Microsoft\Shared Tools\Proofing Tools\1.0\Override\en-US" key pointed to files that were non-existent.

So to solve the problem, all that Jim needed to do was to delete the "HKEY_CURRENT_USER\Software\Microsoft\Shared Tools\Proofing Tools\1.0\Override" registry key. Once this was done, simply by closing and restarting Word, he was able to verify that spell check was once again working.

While for three desktops this may not be a big deal, if you need to remove the Override registry key from dozens to thousands of computers, you probably want an easier way. By default, non-administrators have write permission to their account (HKEY_Current_User) registry hives, so an easy way to apply this fix would be by using the Reg command in your login script. For this specific problem, you ould need to run the Reg command with the following syntax:

Reg delete "HKCU\Software\Microsoft\Shared Tools\Proofing Tools\1.0\Override" /f

The /f switch forces the command to delete the key without prompting for user confirmation.

With multi-language support ingrained in the Office 2007 proofing tools, it's also important to ensure that a user's Word environment is not set to use the wrong language by default. You can verify the default language settings for a user's Word environment by following these steps:

Open Word 2007.

Click the Office icon in the top left corner of the window and then click the Word Options button.
In the Word Options dialog box, click the Language Settings button.
Finally, ensure that the correct language is selected in the Primary Editing Language drop-down menu