Windows Phone 8.1 brings a modern design, notifications, and Cortana (pictures)

Microsoft revamped its mobile operating system with a fresh design, new notification center, and witty voice assistant named Cortana.

Above you can get a glimpse at the new design, which adds another column of live tiles to the Start screen, so you can fit more information. The design looks much more modern than the earlier versions of Windows Phone.

Along with the extra column of live tiles, you can now set a custom wallpaper for your Start screen. It shows up in your live tiles, and you can use any photo you want.

Cortana is your personal voice assistant, there to help you with (almost) any request. You can ask it to search Bing, set reminders, call or text your contacts, verbally jot down notes, and play music on your phone.

You can also ask questions, such as "What's the capital of France?" and get a response back, which is helpful.

Cortana also shows you a dashboard of information it thinks you want to see, based on your recent searches. This includes local weather reports, sports scores, and top headlines that match your interests. You can change what shows up in your dashboard at any time.

Windows Phone 8.1 finally gives us a place to organize all of our notifications. It's called Action Center and it appears when you swipe down from the top of your screen.

There's a row of common settings, such as Wi-Fi and Bluetooth. Below that, you can view all of your notifications grouped by app.

If pecking your keyboard is slowing you down, you can down swipe to type. That means you can use gesture-based typing to drag your finger around on the keyboard, drawing a line through each letter you want to type.

Another new addition is Wi-Fi Sense, an app that helps you automatically connect with open public wireless networks.

It'll also let you share wireless networks without sharing the actual password, with friends who also have a Windows Phone and also have Wi-Fi Sense turned on.