How to install mineshafter On A Hp 2000 notebook pc with Windows 8.1?

I just got A Hp 2000 Notebook Pc for Christmas and I'm in need of playing Minecraft, See the thing is I don't have The actual Game Minecraft I Have Mineshafter, Every Time I open the game itself it won't go to the Home screen of the game. I'm very frustrated and Will be very grateful to get any Answers.

Added (1). What I mean is That When you open the Launcher Of mineshafter and you press play, It loads but When I restore the browser all you see is the screen of the Launcher and not the Minecraft Screen which leads you to playing the game

Have you tried running the game in a different browser? On your Mineshafter game does it let you know it is compatible with Windows 8.1?

Please let me know the exact Model number of your HP Computer, click on the link below to find out:

http://h10025.www1.hp.com/...itle_r0005

I will watch for your reply, thank you!
**AllinOne83**
I work on behalf of HP