Microsoft today unveiled a subtle but important change to its Microsoft account, making it easier for users to switch this account—which is used with Outlook.com, SkyDrive, Windows 8/RT, Windows Phone, Xbox, Office, and other products and services—to a different identity. Now, instead of the previous and unreliable renaming process, you can simply uses any alias as if it were your actual Microsoft account.

Confusing? Don't feel bad: It took me several read-throughs of today's Microsoft blog post plus refamiliarizing myself with what I had written before to figure it out.

So here's the story.

Microsoft has long offered an alias feature for its Microsoft account. You could sign-in at the Microsoft account web site, and add and remove aliases to your account. These aliases could be either new Microsoft-type (hotmail.com, live.com or outlook.com) email addresses or your own custom email address from another service. And once you created one, you could sign into your Microsoft account using that alias. If you use Outlook.com, you could send and receive email through that alias as well.

What happened, however, was that some users wanted to use that alias as their Microsoft account and perhaps get rid of the original email address that was associated with that account. As I wrote in Outlook.com Tip: Use Email Aliases (Part 2) over a year ago, this process was fraught with possible problems because you had to remove the alias and then rename your Microsoft account. But if you used a Microsoft-type email address for the alias, you had to wait a full 30 days before you could use it again. So there was always the worry that you might lose the address if some other user snagged it at an inopportune time.

With today's change to Microsoft account, the rename option has disappeared. Instead, Microsoft is now referring to each email address associated with your Microsoft account as an alias, and the original email address is the primary alias. So you can now change which of the associated email addresses (e.g. "aliases") is the primary alias. So if you wanted to change from bob@hotmail.com (or whatever) to a more modern address (bob@bobsnewemail.com or whatever), you can do so. And you don't have to delete an alias, wait 30 days, and then rename the primary alias, all while crossing your fingers and hoping it works.

You can create aliases that are associated with your other existing (non-Microsoft) accounts, too. So if you have a Gmail account or whatever, you can add that as an alias and then change your Microsoft account so that your Gmail address is your primary alias. You can still sign-in anywhere in the Microsoft ecosystem (again, Outlook.com, SkyDrive, Windows 8/RT, Windows Phone, Xbox, Office, and other products and services) with any of the aliases.

If you use Outlook.com, you can send and receive mail from any of the aliases as well, though that will only work with Microsoft-type aliases (since you already receive email at Gmail.com or other external addresses).

Here's how Eric Doerr explains it.

"Today, we're replacing rename with a simpler and clearer choice to make any of your aliases a primary alias," he writes. "We've also made it clearer why you might want to do this (and why you might not). Now that you can sign in with any alias, really the only reason to make a different alias your primary one is if you want a different email name to show on your Microsoft devices, like the background of your Xbox or your Windows 8 PC."