As expected, Microsoft has responded to calls for it to add a security feature, similar to Google’s two-factor authentication, which will protect users’ increasingly important Microsoft accounts from attack. Today, the firm announced a “two-step verification” option to Microsoft account, which works across all the services that use this account.

“We’re adding an option so you can enable two-step verification to Microsoft account to further protect yourself,” Microsoft account group program manager Eric Doerr wrote in a post to the Official Microsoft Blog. “Two-step verification is when we ask you for two pieces of information anytime you access your account — for example, your password plus a code sent to a phone or email on file as security info.”

Microsoft previously enabled this capability but only for certain scenarios: editing credit card information, accessing files on another computer through SkyDrive, and so on. But with this update, two-step verification is enabled across all of you Microsoft account activities, regardless of the device.

A typical scenario is a login: You provide your credentials to a web site as usual, but then you must provide a second verification, like a code sent to your smart phone, to proceed.

Two-step verification will be rolled out “over the next couple of days.” You can enable this capability at https://account.live.com/proofs/Manage.

Based on years of experience with Google’s two-factor authentication, I recommend enabling this feature immediately, with the understanding that your Microsoft logins are about to get a lot more painful. Trust me, it’s worth it.