I have a Dell 3721 which comes original with windows 8. I managed it to install ubuntu 12.10 on this laptop, even there was no out of the box drivers. With 12.10 I was forces to install this .deb package couple of times. After installing it, it was ok for some weeks before I have to install it again. Maybe some security updates destroy something which made in necessary to install it again...

http://jas.gemnetworks.com/debian/pool/main/w/wireless-bcm43142/wireless-bcm43142-dkms_6.20.55.19-1_amd64.deb

My problem is, that this package isnt working with ubuntu 13.04 anymore. So I cant use Wifi now. Also my display is almost dark, I cant change the brightness level with ubuntu 13.04. Hope you can give me some advice.

Dell:~$ sudo lspci -nn
00:00.0 Host bridge [0600]: Intel Corporation 3rd Gen Core processor DRAM Controller [8086:0154] (rev 09)
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)
00:14.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller [8086:1e31] (rev 04)
00:16.0 Communication controller [0780]: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 [8086:1e3a] (rev 04)
00:1a.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 [8086:1e2d] (rev 04)
00:1b.0 Audio device [0403]: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller [8086:1e20] (rev 04)
00:1c.0 PCI bridge [0604]: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 [8086:1e10] (rev c4)
00:1c.1 PCI bridge [0604]: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 [8086:1e12] (rev c4)
00:1d.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 [8086:1e26] (rev 04)
00:1f.0 ISA bridge [0601]: Intel Corporation HM76 Express Chipset LPC Controller [8086:1e59] (rev 04)
00:1f.2 SATA controller [0106]: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] [8086:1e03] (rev 04)
00:1f.3 SMBus [0c05]: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller [8086:1e22] (rev 04)
01:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05)
02:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)

@Dell:~$ lsusb
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0a5c:21d7 Broadcom Corp. 
Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. 
Bus 001 Device 005: ID 0c45:64ad Microdia 

@Dell:~$ lspci -nn | grep VGA 
00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)

@Dell:~$ sudo lshw -class network
  *-network               
       Beschreibung: Ethernet interface
       Produkt: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
       Hersteller: Realtek Semiconductor Co., Ltd.
       Physische ID: 0
       Bus-Informationen: pci@0000:01:00.0
       Logischer Name: eth0
       Version: 05
       Seriennummer: xx:xx:xx:xx:xx:xx
       Größe: 100Mbit/s
       Kapazität: 100Mbit/s
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       Konfiguration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8105e-1.fw ip=192.168.2.103 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
       Ressourcen: irq:42 ioport:2000(Größe=256) memory:c0404000-c0404fff memory:c0400000-c0403fff
  *-network UNGEFORDERT
       Beschreibung: Network controller
       Produkt: BCM43142 802.11b/g/n
       Hersteller: Broadcom Corporation
       Physische ID: 0
       Bus-Informationen: pci@0000:02:00.0
       Version: 01
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm msi pciexpress bus_master cap_list
       Konfiguration: latency=0
       Ressourcen: memory:c0500000-c0507fff