Putty + screen issue

[Ecurb123]

Hi all,

I'm using windows putty to ssh into my linux machine which is doing some mining, however I would like to use screen to leave the session running while closing the putty software. The problem is whenever I use the commands I see in the guides to switch screens for example, ctrl+a+n, it seems to be taking these key strokes in the windows application, not the linux terminal. So I have screen installed on the linux machine, I can run "screen" but I can't seem to actually use it. Any ideas?

Thanks,
Ecurb