Change Windows 10 User Name to match Microsoft 365 User Name

[Elizabeth206]

I have changed my Microsoft 365 account to a new account with a new user name.  I reinstalled Microsoft 365 on my HP Laptop.  Now, every time I try to open a Microsoft product it asks me for the password for the old Windows user name.  I think I need to change the HP OEM Windows User Name to match the new Microsoft 365 account user name.  How can I do that?

Elizabeth

[WAWood · Accepted solution]

There are two different "names" you could be referring to -- account name and device name. 

The first is what you use to login and to change that, you go into Settings, Accounts.

The second is the "name" of the device and to change that, do the following:

1. Select Start > Settings > System > About .
2. Select Rename this PC.
3. Enter a new name and select Next. You may be asked to sign in.
4. Select Restart now or Restart later.

[Elizabeth206]

Thank you for your timely and articulate response.  My description of the issue was not as articulate as your response, and so I misled you.  

But your response got me thinking more deeply about what might be going on, and I stumbled into the solution.  I needed to remove old Microsoft account names from within the Microsoft 365 applications.  So it was not an HP OEM Windows user name that was the problem, or the ,computer name.  

Thanks again for your time.