When moving to Windows 10, Microsoft wanted you to start using a Microsoft account for your Windows PC as well. Do you not use the email address of that account you created (probably with an outlook.com email address) at all? Then you can change the email address of your Microsoft account.
If you want to log in to Windows with a different email address, you would think that this is a setting that you adjust in Windows itself. Nothing could be further from the truth, you have to go to the Microsoft site for it. Visit www.outlook.com and sign in with your Microsoft account. Then click on your profile picture at the top right and then on View account. Then navigate to your data (top) and click Manage how to sign in to Microsoft. At this point you will be asked to enter an extra security code. That code can be sent to your email address or to your smartphone. You must then select the e-mail address or telephone number in the drop-down menu and enter the last four digits of the telephone number or the full e-mail address in the field, after which you will receive the code. By entering that code and clicking Send, you can continue.
Add email address
You will now be taken to the page where the primary email address (and possibly the associated phone number) is displayed. If you have no further problems with this e-mail address, you can leave it and simply add a new e-mail address by clicking on Add email address. You can then create a new Outlook.com address or add an existing email address (such as your Gmail address). Please note, in the latter case it is of course not the case that your e-mail from Gmail suddenly arrives at Outlook (if you create an Outlook alias, then that is the case). Click now Add alias. By pressing . at the desired address Set as primary, make the new alias the primary email address.
Change login preferences
When you create an alias in your Microsoft account, you can use it to log in to Windows and your mail by default. In this case, that's exactly what we wanted, but sometimes you just want an alias to receive mail on, without actually being able to log in with it. Fortunately, you can disable that login option for each alias individually. To do this click on Login Preferences at the bottom. Then uncheck the alias with which you do not want to log in.