Yes, you can. You have to configure your router to work in compatibility for G networks.
For such purposes you need at least two subnetworks. One adapter cannot be in the same time in both of them. Thus you cannot do that. If you connect your PC through wireless to another PC, and that PC is connect to the router with a LAN cable that it's doable.
if modem has wireless capablity, then no need for a router
An ethernet cord to connect the XBox to a router or the wireless adapter for XBox to connect to your wireless router.
A wireless USB adapter allows a computer or wireless device to connect to a wireless router. It is needed for any device which is not wired to an internet connection, to connect.
Your router WILL need to be wireless to connect wirelessly to your Xbox, but you can use an ethernet cable if your router is not wireless, straight from the router to the XBOX
If you have a wireless router just get a wireless adapter for the computer. It can be USB or PCI adapter. And connect your new adapter to the router in the same way as you connected the first computer.
No special power adapter is needed, because each device, is charged by it's own adapter. If laptops and desktops are connected by a wireless router, for example, the router will have it's own power adapter. However, to establish a wireless connection with a desktop , a laptop must have a wireless USB Wi-Fi adapter. This particular adapter has nothing to do with powering the device. It simply transmits signals to connect with a desktop, another laptop, PDA, cell phone, etc.
You need an Xbox wireless adapter.
no robots will come out and kill you
You buy a wireless router, wire the desktop and router to the modem, and use the laptop by getting a wireless card or usb wireless adapter.
If you are talking about building of wireless network. Then you need a wireless router and a wireless network adapter (if you have a laptop you might not need it). If you have a desktop you rather will have to purchase a wireless network adapter. Pay attention to what kind of wireless network you are going to build. It can be a, b, g, and n types.
If you want to use internet wirelessly, yes you need a wireless router and a wireless adapter for your PC (usually laptops have it).