This sometimes happens if your contacts folder has been changed to another
type of folder. To handle this, start Windows Mail. Click on Tools, then
Windows Contacts. Right click on the empty space at the right of the
contacts window, then click on Customize this folder. Click on the
triangle,
then Contacts, then Apply, then OK, then the X at the top right of the
contacts window.
To edit a contact, open the contacts window the same way, then click on a
contact you want to edit, click on Edit, and you should be able to edit it.
Note that the contacts list is not use to complete addresses you start to
type. This uses a separate list of the last 29 addresses you sent messages
to instead. This list is very hard to edit; it's easier just to send
messages to
the 29 addresses you want on the list.