A connection via Remote Desktop does not require any special client installed if you connect from a Windows machine .
Connect
Access one of the two portals and login with your e-mail and the code you have been given.
Your reseller should have informed you which URL you should use.
Now click on the desktop that is available.
Tips
Via the gear wheel in the top right corner, under settings you can decide whether the session should start in the browser or download a full client.