Outlook Express 6 - import/export

Had to export my messages prior to pc restore. Once completed, I am having trouble getting OE to import the messages back again. Using XP. Have tried File, Import, Messages, Selected OE 6, Next, Import mail from OE6 store directory, OK, Browsed to the dir containing my .dbx files, OK, then it gives me an error, "No messages can be found in this folder or another application is running that has the required files open."

 

Any input?