安装sql server 2016报错
找了国内外N多解决办法，折腾了2个小时弄好了。
先出现的问题是“Microsoft Visual Studio 2010 可再发行组件 / Microsoft Visual C++ 2010 Redistributable Package ”引起的，
Windows Installer 不允许更新经过管理的播发产品。应用更新程序之前，必须至少安装产品的一个功能。原因是 它可能已经在 Visual Studio 中注册了加载项。现在由于插件被删除、但在 Visual Studio 中没有反注册，造成后者认为其依然存在，所以阻碍了正常的重新安装过程。请重新安装删除的插件，然后用 Windows Installer Cleanup Utility 清理一下残留的 Visual Studio 注册信息 [按照这篇文章的指引，先用Windows Installer Cleanup Utility这款工具，把Microsoft Visual C++ 2010 x64 Redistributable给清除了
然后重新安装Microsoft Visual C++ 2010 Redistributable Package（注意x86和x64）：
https://www.microsoft.com/en-US/download/confirmation.aspx?id=5555
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这个弄完后，前面的错误不报了，又报个新错误
标题: Microsoft SQL Server 2016 安装程序
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出现以下错误:
Error 1402.Could not open key: UNKNOWN\Components\{guid}\{guid}. Verify that you have sufficient access to that key, or contact your support personnel.
1.open the registry
2.locate the HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Components\{guid} key and attempt to open
3.grant full access
注意，第2步的时候，Typically an "Access Denied" error will be generated if the issue above is occurring.这个时候就要用到后一片文章里说的工具psexec 。
1.Download and install psexec utility from the following link： http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx
2：Open a command prompt (on Vista/Windows 7/2008) using ‘run as administrator’ option, for Windows (2000 /XP/2003) Hold down the shift key and right click on command prompt and choose run as.
3.In the command prompt Navigate to the folder where PSEXEC is installed.
4.Execute the following from the command prompt： psexec -i -s cmd.exe
5.This will invoke another command prompt running under ‘Local System’（这一步就是当前登录的用户）
6.Using this command prompt open Registry Editor ：
regedit7.In registry editor navigate to the following hive：
HKLM\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Components\8. Add the user account used to run the installation under permissions for the above hive and grant ‘Full control’ for that user.
9.Under the Advanced security settings for Components choose the user and check the “Replace all existing inheritable permissions…………” check box as shown below and click OK
10.Re-run the installation.