Outlook Express 6 spell check error

I have a user running Windows XP Pro and Outlook Express version 6. She can't do spell check for some reason and gets the following message:

"An error occured while the spelling was being checked"

Does Outlook Express rely on or share the spell check features from MS Office or does it have it's own spell check dictionary? If it does, where are the files and what do I look for? Also, how do you re-install Outlook Express? Windows XP doesn't make removing and re-installing Outlook Express very easily. Any help would be appreciated.

Thanks in advance.