WIFI not working

I have a Gateway desktop and Wifi not working tried ever thing i could..

working with this::::
00:00.0 RAM memory: NVIDIA Corporation MCP61 Memory Controller (rev a1)
00:01.0 ISA bridge: NVIDIA Corporation MCP61 LPC Bridge (rev a2)
00:01.1 SMBus: NVIDIA Corporation MCP61 SMBus (rev a2)
00:01.2 RAM memory: NVIDIA Corporation MCP61 Memory Controller (rev a2)
00:02.0 USB controller: NVIDIA Corporation MCP61 USB 1.1 Controller (rev a3)
00:02.1 USB controller: NVIDIA Corporation MCP61 USB 2.0 Controller (rev a3)
00:04.0 PCI bridge: NVIDIA Corporation MCP61 PCI bridge (rev a1)
00:05.0 Audio device: NVIDIA Corporation MCP61 High Definition Audio (rev a2)
00:06.0 IDE interface: NVIDIA Corporation MCP61 IDE (rev a2)
00:08.0 IDE interface: NVIDIA Corporation MCP61 SATA Controller (rev a2)
00:08.1 IDE interface: NVIDIA Corporation MCP61 SATA Controller (rev a2)
00:09.0 PCI bridge: NVIDIA Corporation MCP61 PCI Express bridge (rev a2)
00:0b.0 PCI bridge: NVIDIA Corporation MCP61 PCI Express bridge (rev a2)
00:0c.0 PCI bridge: NVIDIA Corporation MCP61 PCI Express bridge (rev a2)
00:0d.0 VGA compatible controller: NVIDIA Corporation C61 [GeForce 6150SE nForce 430] (rev a2)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
01:05.0 [size=200][color=#FF0000][size=150]Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02)[/color][/size][/size]
01:09.0 FireWire (IEEE 1394): Texas Instruments TSB43AB23 IEEE-1394a-2000 Controller (PHY/Link)
03:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8039 PCI-E Fast Ethernet Controller (rev 14)

Try this.
Plug an ethernet cable to get internet, open terminal and run the following commands:

sudo apt-get remove --purge bcmwl-kernel-source
sudo apt-get install b43-fwcutter
sudo apt-get install firmware-b43-installer
sudo modprobe -r b43
sudo modprobe b43