Windows 7 Internet Connection Sharing (ICS) questions

The wireless card on my desktop died not long ago, and currently as a short-term solution am using Internet Connection sharing through my laptop so that I can connect my desktop to the internet. My laptop and router have wireless-N, so it kind of makes up for the speed drop with using ICS. I have a couple of questions though:

1. 
   Whenever I try to use an application (like a game or bittorrent), it always says the NAT is restricted. I understand why this is happening, because my router has uPnP enabled but because of security issues with sensitive files on my laptop I have a firewall that doesn't really allow inbound traffic. I'm currently trying to open the ports in ICS for a few applications (such as steam) that use an array of ports for inbound traffic (such as TCP 27000 to TCP 27015), but ICS only allows you to add one port at a time, and if I have to add an array of like 15-16 ports that could take a long time. I figure ICS must interface with windows firewall, so I guess my question is can I skip ICS and just directly open the ports in windows firewall, using the host computer (the laptop) as the IP address/name?
   
   
2. As it stands right now, I have the laptop connected to my router via wireless-N, and the desktop connected to the laptop using gigabit connections with a crossover cable. Is there a way to share my files between the laptop and the desktop only, without exposing them to the entire network? (I figure there must be, since I need 2 networks on my laptop to make ICS work).

Thanks guys!

 

I'm not sure about this but I would say to definitely try entering the port range in Windows Firewall as you mentioned and see for yourself if it works. I myself was thinking if you could have possibly used the Internal port as the starting port and the External as the end port # but doing a quick research proved that thought wrong ; that's for something different. Like a type of NAT/Port mapping. So yea, I say give Windows Firewall a try and see if it works! BTW, you mentioned uPnP being enabled on your Router; if that’s the case then all ports that you want/need to access should be forwarded automatically. (once the service is enabled on your computer) Because if I understand correctly, uPnP is a type of service that maps ports to a client machine requesting any given particular service from the Internet once it’s supported by uPnP. So IMO, if you want to have a very secure network, uPnP being enabled on the Router might not be a good thing.

About the sharing files between the two computers only; The feature built-in to Windows 7; HomeGroups might be able to do just what you want here. But this will mean that both computer systems would need to be running 7. If that's not the case here then creating a Network Map of the shared folder/files might do the trick. But to do this, File/Printer sharing must be enabled and the proper sharing/security permissions must be setup. Then you just enter that shared path for ex. \\serratedcomputer\ shareddocsfolder into the network map, choose a drive letter, choose the reconnect @ logon option and you should be good to go. The shared "drive" would always be in your "My Computer" explorer folder as a "network drive".