This tutorial explains how you can get x11 forwarding working for Windows and git-bash (Not putty). Putty has another way of doing this.
- Install Xming: http://sourceforge.net/projects/xming/
- Run Xming from the programs.
- Open GitBash from the Start Menu.
- Export display environment on the bash command.
export DISPLAY=localhost:0
- ssh to the target machine with x11 forwarding enabled
ssh -XY me@myhost
- Try your x11 forwarding e.g. nautilus on the target machine.