If you have any intention of downloading the Alexa App for windows 10 PC. Then, You can simply visit the Microsoft store available in the taskbar at the bottom of your windows 10 PC. Microsoft store needs a Microsoft account to verify you. If you have so then you can search for Alexa App there and install it. Launch your Alexa App and sign in with your Amazon account details. Follow the instructions Alexa App gives you in order to set it up on your Windows 10 device. That is how you can set up the Alexa App for windows 10 pc.