Win 10 changed my user name (Mail issue?)

You can switch back to a local account following these instructions: Local Account - Switch to in Windows 10 - Windows 10 Forums

Kari

As you described what has happened, it looks that you have switched your local account to an MS account (accidentally, maybe, but by yourself; Windows does not do it without your acceptance).

You can check if your user account is now an MS Account by going to Settings > Accounts:

According to your post, this is your case. Your original local account has been switched to an MS Account. Following the instructions in the tutorial I mentioned, your original local account will be restored.

Kari

A year and a half since last post, now some wrong information that needs to be corrected.

xychromosone said:

Just for those who find this thread, my current understanding from experience is if you first install Windows 10 and not use a Microsoft email address [with hotmail, outlook or live etc.], but just create a username, then you have created a "Local Account".

When installing or setting up a pre-installed Windows 10 Home, Single Language or Pro edition, you can choose if you want to set it up with a local account or a Microsoft account. See tutorial: Windows 10 - Clean Install (step 21 for Microsoft account, step 22 for local account).

xychromosone said:

However as soon as you use Windows 10 Mail with a microsoft email address within your local account, then Windows automatically links that with the local account, and you can use that email address and password to sign into Windows 10, which is then referred to as a "Microsoft Account".

Wrong.

When signed in to Windows with a local account and setting up any Windows app that requires a Microsoft account, user can select if he / she wants to continue to sign in to Windows using the original local account and only sign in to that app with Microsoft account, or to convert the whole Windows user account to a Microsoft account.

For instance when a local account user sets up an email account in Mail app, setup will show this prompt:

User can clearly make a selection, by entering a password and clicking Next user converts his / her current local account used to sign-in to Windows to a Microsoft account.

However, as is also clearly shown in prompt, user can select "Sign in to just this app instead". Choosing this option would set up Mail app with user's email account but let user continue to sign in to Windows with a local account.

xychromosone said:

Then as you found, which I do not agree with btw, for you do not seem to have any choice in the matter, Windows creates or changes your user folder's name to your email address username.

Wrong.

Windows never changes the user profile name, nor does it change the name of the user profile folder in C:\Users.

An example: A user sets up Windows 10 using a local account John. His user profile and folder will be named as John. Later on this user decides to convert, switch to a Microsoft account Top.Gamer@AnyEmailProvider.com. He would now sign in to Windows using Microsoft account Top.Gamer@AnyEmailProvider.com but his user profile folder would still be C:\Users\John.

A bit later the same user decides to switch back to a local account and changes his username to Larry. Now he would sign in to Windows using local account name Larry, but his user profile would still be in C:\Users\John.

   Note

Name of the user profile remains the original one regardless how many times username will be changed or how many times users switches between local and Microsoft accounts

.

xychromosone said:

If it has a split name e.g., deadly.eddy@notmail.gom, the folder will be named "deadly" without the ".eddy" part, [note that I purposely changed the hotmail with notmail and com for gom for spam purpose]. If the email address has just one word as the username, then the folder will be named that username e.g., a hotmail email address named deadly@notmail.gom the user folder will be named "deadly".

Partly wrong.

If a new user account is created using a Microsoft account, the user profile name will be a five character abbreviation made from the part of the email address before the @ sign.

For instance in case of your example, the user profile folder would be named as deadl (five characters). User john.doe@SomeEmailProvider.com would get user profile folder named as johnd, user joe.doe@AnotherEmailProvider.com as joedo.

However, if user had a local account named as TheMonsterGamer when he switches to Microsoft account xyz@AndAgainSomeEmail.com, his / her user profile would remain as TheMonsterGamer.

   Note

• Setting up Windows with a local account = user profile folder will be named exactly as user account name, and it keeps this name through all username changes and if user switches to a Microsoft account
• Setting up Windows with a Microsoft account = user profile folder will be named with a five character abbreviation, and it keeps this name through all username changes and if user switches to a local account
• Short: user profile name and user folder name will never be changed when username is changed or user switches from local account to a Microsoft account or vice versa

Kari