Fix: Windows 10 “Email Already in Use” When Switching to Microsoft Account

When you try to switch your local Windows 10 account to a Microsoft (online) account, you may run into the error message:

“This email is already in use.”

This issue often happens when the same Microsoft email (for example, Gmail used as a Microsoft login) is already added under Family & other users.

Why This Error Happens

Windows creates a separate local profile for every user added under Settings → Accounts → Family & other users.
If you added your Microsoft email there earlier, Windows treats it as another user — even if it’s the same email you’re now trying to use for conversion.

So when you try to “Sign in with a Microsoft account instead,” Windows blocks it, saying that the account is already in use.

Before You Start: Protect Your Data

When you remove a user account from Family & other users, Windows warns that all data related to that account — desktop files, documents, downloads, and settings — will be deleted.

To avoid any data loss:

1. Identify your current account:
   • Go to Settings → Accounts → Your info.
     • If it says “Sign in with a local account”, you are using a local account.
     • If it says “Connected to a Microsoft account”, you’re already online.
2. Backup important folders:
   • Copy your Desktop, Documents, Downloads, Pictures, and Music folders to a safe location, such as your F: drive or an external USB.

Step-by-Step Fix

Step 1: Check Your Current Account

• Press Windows + I → Accounts → Your info.
• Confirm whether you are signed in locally or online.
• Note down your current username (e.g., Anton).

Step 2: Remove the Conflicting Gmail Account

1. Go to Settings → Accounts → Family & other users.
2. Under Other users, find your Gmail or Microsoft account that’s marked as an Administrator.
3. Click Remove → confirm with “Remove account and data.”

Don’t worry: This only deletes that secondary profile, not your main local account.

Your files under C:\Users\[YourLocalUsername] stay intact.

Step 3: Sign In With Your Microsoft Account

1. Stay in Settings → Accounts → Your info.
2. Click “Sign in with a Microsoft account instead.”
3. Enter your Microsoft credentials (Gmail address and password).
4. Windows will now link your local profile to your Microsoft account.

Step 4: Verify Successful Conversion

Once done, you’ll see your Microsoft email displayed under Your info, along with your profile picture (if set).
Now your local profile is linked to the Microsoft account — no duplicate profiles, no lost data.

Step 5 (Optional): Enable ESU Free Upgrade

As an EU citizen, you can claim 1 year of Extended Security Updates (ESU) for Windows 10 at no cost once your Microsoft account is active.

Check Microsoft’s official support page for your eligibility and sign-in requirement.

Read More:

• How to Remove a Failed Printer in Windows 11 When It Says “Connect to Remove”
• How to Reset Child Account Password from Parent Account in Family Settings (Microsoft, Google, Apple Fix Guide)
• Windows 11 File Sharing Not Working? Full Fix to Connect Two PCs Easily

This issue is common among users who originally used a local Windows account and later added their Microsoft email under “Other users.”

By removing the duplicate entry and signing in properly, you can safely connect your account online and unlock benefits such as automatic syncing, OneDrive integration, and the free ESU 2025 upgrade for eligible users.