What was the nature of the prior board failing? Struck by lightning, power supply failure, etc?
Its quite possible that the wireless adapter is bad, damaged by the prior build that the motherboard died on.
If you need wireless networking and don't want to bother with a card. You can pick up a USB Wireless Adapter pretty cheap these days such as at Newegg, Tiger Direct, or another online store that sells computer parts and accessories. I even added one of these to an old Dell laptop that had a single USB 1.1 slot, which ran Windows XP SP2 and the wireless adapter allowed for this laptop to have wifi. These same adapters can also be used in desktop computers to connect them to a wireless network. My daughters Core 2 Duo E4500 system for example is connected via a 5 year old Netgear USB network adapter to Wireless-G because I didn't want to drill holes in the walls and floor/ceiling to route Cat5e cable.
For less than $15 these USB network adapters can be picked up online and they work well in the home. If you were connected to wifi from a specific location in your home prior, they work fine, however due to their compact design they lack the range of other better USB adapters or Internal Card Adapters due to antenna length and transmission strength. My Pentium III Dell Laptop with the USB NIC I was able to see open networks to connect to that showed 1 bar strength in a college town for example, but while the adapter was able to see the wireless router/access points, it wasn't able to yell loud enough to make its radio signal voice heard by these network devices. * So if you have a good signal in your home you would probably have no troubles with this USB NIC option because its radio signal voice to router or access point can be heard by the device serving up the wifi.
