Wireless adapter problem

I just encountered a problem with my laptop. I logged on and when I tried to go on the internet, it wouldn't connect. My laptop runs vista and uses a Broadcom 4321AG 802.11a/b/g/draft-n Wi-Fi Adapter. When I went to the device manager it wasn't listed under network devices. I checked the event viewer and it said "The device 'Broadcom 4321AG 802.11a/b/g/draft-n Wi-Fi Adapter'(PCI\VEN_14E4&DEV_4328&SUBSYS_1366103C&REV_03\4&34409144&0&0010) disappeared from the system without first being prepared for removal." If anyone could help me out with this I would appreciate it.