Red Pitaya PuTTY connection

[blacksea680]

I'm trying to connect to my RP (STEMlab 125-14) through a PuTTY connection, but it says connection rejected every time. I realized that typing the RP IP address into the browser did not work, and that the orange LED was not on at all, so I tried installing the newest versions of SD images for Windows following instructions.
The first one I tried was Latest Stable 125-14/10, which did not change anything. The second one was Latest Beta 4-Input which now I have only green and orange non-blinking LEDs. I'm not sure what I'm doing wrong, is the problem not about the SD at all? Is there another way to make a connection through PuTTY?