出现以下这个错误时：

BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>

1.用vi文件编辑工具在linux创建一人新文件“apt-wilson.sh”;

sudo apt-get clean
cd /var/lib/apt
sudo rm -rf lists.old
sudo mv lists lists.old

gpg --delete-key --armor 40976EAF437D05B5
sudo apt-key del 40976EAF437D05B5

gpg --keyserver-options http-proxy --keyserver keyserver.ubuntu.com --recv 0976EAF437D05B5
gpg --export --armor 40976EAF437D05B5 | sudo apt-key add -

sudo mkdir -p lists/partial
sudo apt-get clean
sudo apt-get update

2.然后用命令行"./apt-wilson.sh"执行它

执行完成后还有以下错误

W: GPG error: http://mirrors.aliyun.com precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
W: GPG error: http://mirrors.aliyun.com precise-updates Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
W: GPG error: http://mirrors.aliyun.com precise-backports Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5
W: GPG error: http://security.ubuntu.com precise-security Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5

3.然后再执行以下命令行：

apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5

4.最的再执行下面的命令行应该就没有问题了

apt-get update

apt-get 的种种问题