Hands-on with the new Windows 10 Build - 10162 . Lets start . This build seems pretty more stable than the previous builds . As Gabriel Aul says this build has bug fixes and better battery life , it is indeed true...

                                   Hands-on and First Appearance                                         

Windows 10 Desktop
This is what you'll be seeing the first time you open the Windows 10 Desktop . This is likely to stay by the time RTM build arrives to everyone on 29th July 2015.
What's New.....
Start

Critically the Start Menu is back. It contains standard Windows software and Windows apps. Modern UI apps, as they used to be called. Or Metro apps, if you want to go right back to the beginning.

Start menu in Windows 10
This start menu looks to be better and more usable. For example ,  you'll see a list of your most-used apps on the left, just as in Windows 7 but with a catch : You just cant pin anything over there. At the bottom we see an 'All apps' shortcut, plus when you open start menu for the first time , you'll shortcuts to File Explorer, Settings and – conveniently – shut down and other power options.

For those Windows 8.x fans out there , fret not . Microsoft has retained the Windows 8 Start Screen functionality on the right side of the Start menu. Basically you call it a hybrid of Start in Windows 7 and Windows 8 . Further , this start menu is resizable , both horizontally and vertically - one which you couldn't get with Windows 7 start menu.
Search and Cortana
Cortana and Search combined
Instead of placing a search box in the Start menu like in Windows 7 , or hiding it completely as it was with Windows 8, in Windows 10 the search bar sticks front and Centre on the Taskbar next to the Start Button. In my view , This is rather another smart move from Microsoft, as it’s always there ready to serve up whenever you want or whatever you want to find.

The first time you click on the box, you’ll see a prompt to enable Cortana. That’s because Cortana and search are pretty much one and the same in Windows 10. You can enable Cortana in regions that support it , or you have the normal search behavior where you don't get Cortana.

Windows Phone 8.1 users have had a natural access to Cortana . Yes , its the same in Windows 10 too . You can type and talk to her or press the microphone button or you can even say "Hey, Cortana"...


Search , showing installed apps ,
related settings , web search
Sticking with search , type a word and you'll see a list of apps installed on your PC - be it the trusted Windows Store Apps or the Desktop apps. But there’s lots more you can do, as all the features from Windows Phone are now in Windows 10. So you can type or ask, “What’s the weather going to be like this weekend?” and Cortana will display a forecast.
Cortana will show the top news stories, identify music playing and has a ‘Daily Glance’ which displays a summary of your meetings, today’s weather, information about your daily commute, sports scores and more. If you allow it, Cortana can access information from emails, such as flight numbers and warn you if there’s a delay or if there’s heavy traffic on the way to the airport and you need to leave earlier than you might have.
If Cortana can’t answer a question directly, it will launch the new Edge browser (or whichever browser you set as default) and display search results , which I think is a bit awful as in Windows 8.1 we had Bing Smart Search and the search could directly display results in an app (sort of) .
Finally, Cortana can set alarms, record notes, play specific music, launch apps and give you directions on a map. We think Cortana is great, and one of Windows 10’s biggest draws. Learn how to use her capabilities, and you’ll sure to be more productive.

Virtual Desktops , Alt-Tab , Task View
To the right of the search bar you see a new icon . Tap it and Task View will open. It’s a lot like the view you get in Windows 7 or 8 when you press Alt+Tab. You can still use Alt+Tab in Windows 10 but the shortcut for Task View is Win+Tab.
Task View in Windows 10 showing Virtual Desktops and running apps in each desktop
Along the bottom of the screen, beneath the app thumbnails is a new bar showing virtual desktops. This is a feature many Windows users have been behind Microsoft since ages, and Redmond has finally listened to them . Now in Windows 10, you can create virtual desktops right out of the box. It’s a simple case of clicking the Add desktop button and you’ve got a new, blank desktop on which to launch apps.
Then you can quickly flip between desktops using Ctrl+Win+Left cursor or Ctrl+Win+Right cursor (I do have issues with Ctrl+Win+Right). This is much faster than using Alt+Tab and trying to find one Word document from several open windows.

Snap Assist and Virtual Desktops
Until Windows 8.1 , a snapped app used to take up half the real estate of the desktop . But this is changing with Windows 10 . You can now have upto 4 apps snapped together , each occupying a quarter of the real estate . When you’ve snapped an app, Snap Assist will display an Alt+Tab (sort of) view of some of the remaining open apps so you can quickly fill the entire screen.
Snap Assist +Quadrant Snap in Windows 10 ; Pretty useful for everyone
You can still snap apps to fill the whole screen, or the left- or right-hand side, and the same shortcuts apply as with Windows 7 and 8.
Notifications
Notifications , from Metro apps began since Windows 8 . But this experience is getting better with Windows 10 . In Windows 10 , there is a new Action center,complete with toggle buttons for common settings; which allows you to view notifications you've missed . This was lacking in Windows 8.x .
The shortcut to display Action Center in Win+A .