firefox proxy

To connect to a remote computer and use it as a proxy do the following.

Open Tools->Options->Advanced->Network
SOCKS Host 127.0.0.1 Port 8080
select SOCKS v5

Now open a tunnel in Cygwin+Poderosa by
ssh -C2qTnN -D 8080 usernam@server

Alternatively, you can do the same using Putty.
For this set up a putty connection with details like host, auto login name etc.
Then load your private key to the server in the pagent.
Now to create the tunnel in putty,
Connection->SSH->Tunnels
In the source port type 8080
select Auto and Dynamic and hit Add.
This will add D8080
Now save those settings and open the connection.