That won't work if there are no duplicate contacts in People. You won't get any error message because there is no error to report.
I have In my Windows Live Mail I have some 50 contacts, and half of them are duplicates. Of each pair of duplicate contacts, one contact is labeled "Address book" and the other is not. The one marked "Address book" can be edited or deleted. The other contact cannot be edited or deleted.
Neither of your suggestions work at all and there are no error messages to report.
This has obviously been going on for years and MS can't sort it out.
This is how it works on Windows 7-
So here goes..
Make sure you have all your contacts on your outlook.com people list, and all duplicates have been removed.
Download a copy of you contacts as a backup.
Close Windows Live.
On your PC navigate using Windows explorer to
C:\users\username\appdata\local\microsort\windowslive\contacts. (where username is your login name)
In the contacts folder you will find a folder named the same as your email address - delete the entire folder.
Open Windows Live, sign in and your contacts should be the same as your Outlook.com list.