You can use the Link duplicate contacts tool to clean up your contacts. This tool identifies contacts that have multiple entries and gives you the option to link them so they appear as a single contact. You can unlink contacts later if you wish.
Link duplicate contacts in Outlook.com using the tool
Sign in to Outlook.com.
At the bottom of the page, select .
In the command bar at the top of the page, select Manage > Link duplicate contacts
Note: We recommend linking contacts in batches of fewer than 50 contacts at a time.
Link contacts manually
You can also link contacts manually:
On the People page, select two or more contacts, and then select Link contacts in the panel on the right.
On the People page, select the contact that you want to unlink.
Select Linked contacts on the toolbar, and then select Unlink next to each contact you wish to unlink.