Last year, Microsoft and Amazon announced something completely unexpected -- that their respective digital assistants, Cortana and Alexa, would soon work together. That partnership took a year to come to fruition, but better late than never.

Rather than a cat-and-mouse competition, the two assistants will instead lean on each other to fill the gaps in their abilities.

Alexa users can call on Cortana for things like sending an email via Outlook with your voice or manage your calendar. Likewise, Cortana users will be able to call upon Alexa to use one of her thousands of skills or control the smart devices around their home.

Here's how to set it up.

Connecting Cortana and Alexa

For starters, you will have to pair the two services, which means you will not only need an Amazon account but also a Microsoft account.

Beyond that, you will need a Windows 10 computer and an Amazon Echo ( ) or Tap speaker (Cortana does not yet work with the Alexa app or with third-party Alexa-enabled speakers).

Now playing: Watch this: Amazon's Alexa and Microsoft's Cortana can talk to each...

Using the Cortana skill

The easiest way to pair the two assistants is by enabling the Cortana skill using the Alexa app on Android or iOS (or the Alexa web client).

In the app's menu, tap Skills. Search for Cortana and tap Enable. This will prompt you to link your Microsoft account. (If it doesn't automatically, tap Settings on the skill page, then click Link Account.) Click I agree and sign in with your Microsoft account credentials.

Once you've enabled the Cortana skill, you can interact with Cortana by saying, "Alexa, open Cortana."

The first time you use Cortana, you need to give it access to your device address. To do this, open the Alexa app, go to the Cortana skills page and then Settings > Manage Permissions.

After it's fully setup and you summon Cortana through your Alexa speaker, you can talk to it just as you would through your Windows computer.

For now, the Cortana skill is rather limited, so not all features are enabled. The skill page even lists the Cortana skill as a public preview and it's not available on third-party Alexa-enabled devices.

Using Alexa on Windows

Taylor Martin/CNET

Adding Alexa to Cortana is a little different, and you can't do it with your phone. Instead, you'll need a Windows 10 ( ) PC.

That said, it's just as easy. Open Cortana by clicking the icon in your taskbar or by pressing Windows key + S.

Then type or say, "Open Alexa" and a window will appear. Log in with your Amazon account credentials and click Sign in. Click Allow to confirm the connection and click either Yes or Skip when asked if you want to allow Windows to remember your Amazon login information.

Finally, click Yes in the Cortana menu to allow Microsoft to share your location and recorded audio with Amazon. All this means is that Microsoft is recording the audio but passing it along to Amazon so Alexa can parse and interact with what you say.

After Alexa is fully connected with Cortana, say, "Open Alexa." You can then begin talking to Alexa as you normally would.

You can use your favorite Alexa skills directly from your Windows desktop, control your smart lights or even cue up music on Alexa speakers around your home.

Now that you have Alexa and Cortana working in harmony, consider these 50 Alexa skills.

Or peruse our constantly updated list of Alexa commands to try.