Now-a-days everyone is linking accounts and data, rather than keeping them in sync. So if you have multiple accounts with an addressbook or contact list, it makes it hard to keep them up-to-date, especially once you unlink them.
1. First export your contacts from your program or web app of choice. For me it was Google’s Gmail.
2. Then from Hotmail, click on Contacts, Manage, then Import.
3. Remember, clicking on an app will link the contacts, not sync. We must choose ‘Outlook’, which will take you to an upload form.
4. Browse and attach your csv and upload.
5. After the upload is complete, you will have the option to merge duplicate contacts.