Go here and download the automated install files.
http://sdrsharp.com/downloads/sdr-install.zip
Unzip the three files in that zip file.
Then doubleclick on the 'install.bat' file that was unzipped.
Give it some time to finish downloading all the files.
That will create a folder named 'sdrsharp' that contains everything you need.
And you can run it from that folder if you want.
You also need to do this:
Install the driver (zadig) per instructions here.
Zadig - USB driver installation made easy
You should be good to go.
But, you also need to make sure you have .net framework 3.5 installed.
Rich
Edit: Some additional zadig info if you have problems....
https://github.com/pbatard/libwdi/wiki/Zadig