Traditional remote exploits are performed by taking advantage of a vulnerability in a listening network service. If you have no listening network services (e.g. if all your ports are "closed") then you will not be able to exploit the system using remote exploits. Pretty simple really.
Install a vulnerable listening service on your Windows 7 system and you should then be able to attack it. Alternatively, you could try a client side exploit on your Windows system.
I suggest you have a look at Metasploit Unleashed, and I have also written some exploit writing tutorials you can find links to from our HowTo forum if you want something more challenging and if you want to understand how this stuff works.