contacts in windows live cannot be deleted as from field is blank

I am using Windows live mail and I find some 97 contacts where the From field is blank and hence windows live mail does not allow me to delete the same. In case of other contacts the From field has "Address book", "Linked in" and "Face book". I know I cannnot delete "Linked in" and "Face book" contacts as they come from these sites, but how do I delete the contacts where From field is blank. Also, when I did a search for contacts.edb, I find there are multiple contacts.edb on my computer and it seems that this may be causing the problem. So if I know which one to keep and which one to delete ? then may be the issue gets resolved.