You will need Putty to generate a SSH key easily and quickly. You can download Putty here.
After installing open up PuttyGen, you can find this application when opening start menu and search for "PuttyGen".
Make sure the type of key is set on "RSA" and press "Generate", you will be asked to move your mouse a few times over the grey area. (This way it renders a unique pair)
After this has been done, you will have a keypair generated. You can save this by pressing "Save public key" and "Save private key", save both to a secure file location.
You will need these keys to connect to your server.