I live in a dorm where the internet is 802.1x protected. Therefore I cannot use my Macs internet sharing abilities for use with the Xbox 360. My only option really is to use the Internet Connection Sharing (ICS) capability of Windows to hook up my 360. I tried doing this with Windows XP SP3 on Parallels and when I look for the Internet Connection Sharing tab, it is not there. It should be directly under the firewall settings. Here is a link as to how to hook up a windows computer this way: http://www.dhnet.ufl.edu/getconnected/tutorials/wired/ics/xbox_xp/text.php In step # 6 I do not see the "Internet Connection Sharing." Any ideas as to how to fix this?
Please describe the environment more. I expect your configuration is something like this: Your Mac OS have two network interfaces: first is Airport, by which you connect to the Internet and second is is Ethernet, which is connected to Xbox. Your Windows VM has two network adapters: first one is Shared (by which VM connects to the Internet) and second is Bridged to Ethernet, to provide network to the XBox. - If it is not so, please describe your case.
