A lot of users who use Win8.1 are computers bought back to install the Win8.1 system, and others have been set up to use the local account login system. In this way, you can switch to a Microsoft account in a variety of ways. Let's look at it together.
Operation method
Swipe from the right edge of the screen, click "Settings" and click "Change Computer Settings". (If you use the mouse, point the pointer to the lower-right corner of the screen and move up, click Settings, and then click Change Computer Settings.) Click or click Accounts, your account, and connect to Microsoft accounts in turn. You may be asked to verify your current password. Then, select one of the following options:
Option 1: Connect to an existing Microsoft account
Even if you are not using a Microsoft account to log on to your computer, but you are using other Microsoft services (such as Xbox, Hotmail, Outlook.com, or Skype), you may already have an account. Your Microsoft account is the e-mail address used to log in to these services.
Enter the e-mail address and password you used to log in to other Microsoft services, click or click Next, and then follow the instructions.
Option 2: Register with your most commonly used e-mail address
If you have not used Microsoft services in the past, you can use any e-mail address, including the Outlook.com, Yahoo!, or Gmail address, that you want to use to register your new Microsoft account. Use your usual email address:
Enter the e-mail address you want to use, and then click or click Create New account.
Follow the instructions, fill in your personal and safety information, and everything is done.
Option 3: Get a new e-mail address
If you want to start from scratch and get a new e-mail address for your Microsoft account, you can create a free one:
Click or click "Create New Account".
Follow the instructions to fill in your personal and security information for the new e-mail address, and then use the account.
I believe most people don't have a Microsoft account, but the mailboxes are basically there. So just register a Microsoft account with your own mailbox, and then you can use it to log into the Win8.1 system.