Outlook Express query

[Ripley]

Home computer shared. Windows XP with 2 users partitioned.

 

My OE is fine but partner has lost address book and can't compose a mail. Mail received is visible but can't be opened.

 

Error messages indicate configuration error and say reload OE. But mine works.

 

I have system restored to earlier than problem first sighted but that doesn't solve it.

 

Any offers?