Click on Start > Settings > Control Panel.
Double click on System > Hardware > Device Manager
Are there any with a (!) next to them? I'm guessing your network card and wireless network card have them; which means that Windows was probably unable to find and install drivers for them.
If you put in the 10.5 DVD while booted into Windows, is there ay way to tell it to install drivers? I think that is your problem.
If not, then post a reply and we'll see if we can get this sorted out.