You can download Python from here -----> Download Python
And make sure that you download Python 2.7.10.
3)Choose the option Install for all users and choose next.
4)You can now choose the location where to install python.After choosing the location choose next.
5)Scroll down and go to option Add Python.exe to path and click on it and choose Entire feature will be installed on local hard drive option and choose next.
7)Restart your computer.
8)Now open CMD by typing CMD in search box and simply type python to run it.