I had to reinstall Microsoft 365 on my computer and lost my contacts in Outlook

Question

I had Microsoft 365 account but was using Outlook 2016 for email program on the computer. I got a new computer and reloaded M365 64 bit install and was switched to the new Outlook, but I failed to back up the contacts in the 2016 program. Now I don't know where to find that address book. Nothing is showing up in the new Outlook version. I do have Carbonite backup but now sure where that file would be or even if it was backed up. Any thoughts or ideas on how to recover my address book?

Answer 1

I'm glad you were able to resolve your issue. Thanks for letting me know.

Answer 2

When connecting to a Gmail mailbox, classic Outlook uses IMAP. You have probably lost your contacts unless you backed them up. Contacts are kept locally with IMAP accounts in the OST. IMAP is a mail-only protocol and cannot sync contacts. Do you still have access to the old computer? If so, you may be able to salvage the contacts from the OST you had been using. Let me know and I can talk about how you may be able to recover the contacts.

Answer 3

Hi. I'm Brian and I'll try to help.

The AI said "Outlook 2016 contacts are stored in the same Outlook data file as mail (a .pst file for POP/IMAP or local data)." This is incorrect. While PSTs are used for POP accounts or local data, they are not used for IMAP account primary storage. For that, Outlook uses an OST. The issue with an OST is that if you remove the account from the mail profile, you lost access to the OST the IMAP account was using. I suspect you were using an IMAP account. Can you verify that?

Answer 4

Outlook 2016 contacts are stored in the same Outlook data file as mail (a .pst file for POP/IMAP or local data). To recover the address book on the new computer, the key is to locate the old Outlook data file from the old PC or from the Carbonite backup, then open it in Outlook.

Follow these steps:

1. Locate the old Outlook data file in the backup
   • Typical locations on the old PC (these are what Carbonite is likely to have backed up):
     • C:\Users<YourUsername>\Documents\Outlook Files\
     • C:\Users<YourUsername>\AppData\Local\Microsoft\Outlook\
   • In Carbonite, browse or search for files ending in .pst (for example, Outlook.pst). This file contains emails, contacts, calendar, and folders from Outlook 2016.
   • If only .ost files are found, those cannot be directly reused on the new machine; a .pst file is needed for straightforward restore.
2. Restore the .pst file from Carbonite to the new computer
   • Use Carbonite’s restore/browse feature to download the identified .pst file to an easy-to-find folder on the new PC (for example, Documents).
3. Open the restored .pst file in Outlook on the new computer
   • In the desktop Outlook app (not Outlook on the web):
     • Go to File > Open & Export > Open Outlook Data File.
     • Browse to the restored .pst file and select Open.
   • Outlook will add a new data file in the folder list. All old mail, contacts, calendar, and folders from Outlook 2016 should appear there.
4. (Optional) Import/merge into the current mailbox
   • If the old contacts should live inside the current mailbox instead of a separate data file:
     • Go to File > Open & Export > Import/Export.
     • Choose Import from another program or file > Outlook Data File (.pst) and follow the prompts to import into the current mailbox.
5. If using an Exchange/Microsoft 365/Outlook.com account
   • For Microsoft 365, Exchange, or Outlook.com accounts, mail and contacts are normally stored on the server, not in a .pst file, and are recreated when the account is added to Outlook. In that case, sign in with the same account and let Outlook sync. Local-only contacts, however, would still be in a .pst file as described above.

If no .pst file exists in Carbonite or other backups, and the account is not an Exchange/Microsoft 365/Outlook.com account with server-stored contacts, then the old local address book cannot be recovered.

---

References:

• Find and transfer Outlook data files from one computer to another
• Back up your contacts
• How do I recover my old email messages, my contacts and everything else I had in Outlook? - Microsoft Q&A