If the built in driver is not working you can always try to generate one with ndisgen using your Windows Wifi
wireless drivers.
....These are some instructions I posted in PCBSD
Basically use your Win wifi drivers in this example bcmwl5.inf and bcmwl5.sys.
Code:
su
cd to the drivers directory
ndisgen bcmwl5.inf and bcmwl5.sys
....which should produce BCMWL5_SYS.ko
....which you can place in /boot/kernel I also left a copy in my Home dir (for luck

)
Code:
kldload
ndiskldload if_ndis
kldload BCMWL5_SYS
....check all loaded like so
Code:
kldstat
To allow this process to automate on boot place these lines in /boot/loader.conf like so
Code:
kdesu kate /boot/loader.conf
ndis_load="YES"
if_ndis_load="YES"
BCMWL5_SYS_load="YES"
...and save ..
Code:
kdesu kate /etc/rc.conf
....add this line to the end
Code:
ifconfig_ndis0="DHCP ssid default"
....where default is your ssid name
...Anyway really critical if your
Wireless Lan is DHCP (Hands IPs out to NICs)
is to enter the name of the ssid (wifi routers given name)
I am accustomed to having the ssid found automatically by Knetworkmanager with LINUX.
However auto scanning does not work well with some ndisgen converted drivers.
You can also do this in network manager.