我最近在 Windows 7 旁边安装了 Linux。前几天一切都运行良好。然后我决定从 11.10 升级到 12.04。我认为安装最后挂了，因为当电脑重新启动时它冻结了，我不得不用电源按钮强制关机。
之后事情变得很奇怪。即使我从 GRUB 菜单中选择了不同版本的内核，我的 wifi 和以太网也无法正常工作。在 Windows 之间切换以上网并排除故障以恢复到 Linux 执行命令非常麻烦。今天我尝试通过选择 Ubuntu 选项“从 12.04 升级到 11.10”在 12.04 上重新安装 11.10。问题仍然存在，但希望有人能帮忙。
看起来 wlan0 和 eth0 都无法正常工作。我使用常规的“ifconfig”命令无法看到 wlan0 或 eth0（只能看到 lo）。我也无法打开“系统设置”下的“网络”部分。
ifconfig -a
eth0 Link encap:Ethernet HWaddr b8:70:f4:2c:2b:9a
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:41 Base address:0x8000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
wlan0 Link encap:Ethernet HWaddr ac:81:12:a4:7e:a3
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lspci | grep Ether
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)
sudo lshw -c NET
PCI (sysfs)
*-network DISABLED
description: Wireless interface
product: BCM4313 802.11b/g/n Wireless LAN Controller
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:05:00.0
logical name: wlan0
version: 01
serial: ac:81:12:a4:7e:a3
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=brcmsmac driverversion=3.0.0-26-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
resources: irq:17 memory:d6400000-d6403fff
*-network DISABLED
description: Ethernet interface
product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:06:00.0
logical name: eth0
version: 02
serial: b8:70:f4:2c:2b:9a
size: 100Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=N/A latency=0 link=no multicast=yes port=MII speed=100Mbit/s
resources: irq:41 ioport:2000(size=256) memory:d2410000-d2410fff memory:d2400000-d240ffff memory:d2420000-d243ffff
an attempt to activate eth0
sudo lshw -enable eth0
*-network
description: Ethernet interface
product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:06:00.0
logical name: eth0
version: 02
serial: b8:70:f4:2c:2b:9a
size: 100Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=N/A latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
如果默认设置不起作用，我是否需要下载其他程序来接管 ubuntu 中的网络？为什么全新安装（保留个人文件夹）不能解决问题？
答案1
启动 Ubuntu 并转到终端并输入此命令来重置网络的所有硬件开关：
sudo rfkill list all
现在重新启动，一切应该可以重新开始工作了:)