I have outlook 2007 but previously used outlook 2003. When I changed to 2007
I archived all e-mails on an external harddisk. They are stored as
archive.pst.
When I try to open them thorugh the windows explorer they do not open. When
I try to open them through outlook 2007 it gives me error messages and
refuses to open the file.

What can I do?
With hope for help, Messy