How to change primary email address with existing gmail account

The “already exists” message means that Gmail address is associated with another Microsoft account, so it must be removed from that account before you can add it to your current account. An alias cannot be associated with two Microsoft accounts simultaneously.[^1^](https://support.microsoft.com/outlook/something-went-wrong-with-error-addriverstoreaccessnonlocalexception "Something went wrong" with error ADDriverStoreAccessNonLocalException | Microsoft Support)

Release the Gmail address

1. Open the Microsoft sign-in page and try signing in using the Gmail address.
2. If it opens a different Microsoft account, go to Your info → Manage how you sign in to Microsoft.
3. Under Account aliases:
   • If Gmail is the primary alias, first select Add email and create or add another address.
   • Select Make primary beside that replacement address.
   • Select Remove beside the Gmail address.
4. Sign out of that account.

Changing the primary alias alone does not release Gmail; it must be removed from the account’s alias list.^2^

Do not remove the Gmail alias until the other account has a working replacement sign-in address.

Add Gmail to the Microsoft account you want to keep

1. Sign in to the Microsoft account currently using your Comcast address.
2. Open Your info → Manage how you sign in to Microsoft.
3. Select Add email.
4. Choose the option to add an existing email address, enter the Gmail address, and complete verification.
5. Under Account aliases, select Make primary beside Gmail.^3^
6. Sign out and test signing in with Gmail before removing the Comcast address.
7. Once Gmail works, return to the alias page and select Remove beside the Comcast address if you no longer want it attached.

Changing the primary alias keeps the same Microsoft account, password, OneDrive storage, subscriptions, contacts, and settings.^3^

If Gmail cannot be released

• You cannot find the account using Gmail: Use Microsoft’s sign-in recovery options. The address may still be attached as a secondary alias even though signing in does not locate it.
• Gmail was removed but still reports “already exists”: Contact Microsoft Support from the support option on the alias-management page and ask them to review the remaining account association. Support can investigate it, although agents cannot directly change account details.^2^
• The Gmail address belongs to a separate Microsoft account you need to retain: Microsoft personal accounts cannot be merged, and purchases, balances, and similar account data cannot be transferred between them.^4^ You must either release Gmail from that account using the steps above or choose another primary alias for the Comcast-based account.

References

1. "Something went wrong" with error ADDriverStoreAccessNonLocalException | Microsoft Support
2. Gmail wont work when I try to change the alias to a microsoft account - Microsoft Q&A
3. Change the email address for your Microsoft account | Microsoft Support
4. Combining Microsoft accounts | Microsoft Support