问题描述：win10 下无法安装VS2017，visual studio installer下载进度始终为0，点击取消按钮后，也没有反应，visual studio installer也关闭不掉；
具体问题详见 博问：https://q.cnblogs.com/q/106027/ 微软问题：https://social.msdn.microsoft.com/Forums/zh-CN/baafa177-158d-4130-bc64-330b7b32a14c/win10-vs2017visual-studio-installer0?forum=vstudiozhchs
通过查询C:\Users\admin\AppData\Local\Temp下日志（dd_bootstrapper_开头）：
VisualStudio Bootstrapper:2018/5/6 10:05:07: Beginning file download. File = https://aka.ms/vs/15/release/installer.
VisualStudio Bootstrapper:2018/5/6 10:05:07: Download requested: https://aka.ms/vs/15/release/installer
VisualStudio Bootstrapper:2018/5/6 10:05:07: Attempting download 'https://aka.ms/vs/15/release/installer' using engine 'WebClient'
VisualStudio Bootstrapper:2018/5/6 10:05:07: WebClient error 'ConnectFailure' - proxy setting 'Default' - 'https://aka.ms/vs/15/release/installer'.
VisualStudio Bootstrapper:2018/5/6 10:05:07: WebClient error 'ConnectFailure' - proxy setting 'DefaultCredentialsOrNoAutoProxy' - 'https://aka.ms/vs/15/release/installer'.
VisualStudio Bootstrapper:2018/5/6 10:05:07: WebClient error 'ConnectFailure' - proxy setting 'NetworkCredentials' - 'https://aka.ms/vs/15/release/installer'.
VisualStudio Bootstrapper:2018/5/6 10:05:07: WebClient error 'ConnectFailure' - proxy setting 'DirectAccess' - 'https://aka.ms/vs/15/release/installer'.
VisualStudio Bootstrapper:2018/5/6 10:05:07: WebClient failed in 'https://aka.ms/vs/15/release/installer' with '基础连接已经关闭: 无法连接到远程服务器。' - 'https://aka.ms/vs/15/release/installer'.
VisualStudio Bootstrapper:2018/5/6 10:05:07: Download failed using WebClient engine. System.Net.WebException: 基础连接已经关闭: 无法连接到远程服务器。 ---> System.Net.Sockets.SocketException: 无法加载或初始化请求的服务提供程序。
在 System.Net.Sockets.Socket..ctor(AddressFamily addressFamily, SocketType socketType, ProtocolType protocolType)
在 System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6)
在 System.Net.PooledStream.Activate(Object owningObject, Boolean async, GeneralAsyncDelegate asyncCallback)
在 System.Net.Connection.CompleteStartConnection(Boolean async, HttpWebRequest httpWebRequest)
--- 内部异常堆栈跟踪的结尾 ---
在 System.Net.HttpWebRequest.GetResponse()
在 Microsoft.VisualStudio.Setup.Download.WebClientEngine.GetWebResponse(Uri uri, DownloadContext downloadContext, DownloadSummary& downloadSummary)
在 Microsoft.VisualStudio.Setup.Download.WebClientEngine.DownloadCore(Uri uri, Stream stream, ProgressUpdateCallback progress, CancellationToken cancellationToken, DownloadContext downloadContext)
在 Microsoft.VisualStudio.Setup.Download.DownloadEngineBase.DownloadWithBitRate(Uri uri, Stream outputStream, ProgressUpdateCallback progress, CancellationToken cancellationToken, DownloadContext downloadContext)
在 Microsoft.VisualStudio.Setup.Download.DownloadEngineBase.Download(Uri uri, Stream outputStream, ProgressUpdateCallback progress, CancellationToken cancellationToken, DownloadContext downloadContext)
在 Microsoft.VisualStudio.Setup.Download.DownloadManager.DownloadWithRetry(IDownloadEngine[] engines, Uri uri, Stream outputStream, ProgressUpdateCallback progress, CancellationToken cancellationToken, DownloadContext downloadContext, Boolean verifySignature)
VisualStudio Bootstrapper:2018/5/6 10:05:07: Sleeping 5000 milliseconds before retrying download.
VisualStudio Bootstrapper:2018/5/6 10:05:12: Attempting download 'https://aka.ms/vs/15/release/installer' using engine 'Bits'
VisualStudio Bootstrapper:2018/5/6 10:07:12: Skipped BITS download engine: 检索 COM 类工厂中 CLSID 为 {4991D34B-80A1-4291-83B6-3328366B9097} 的组件失败，原因是出现以下错误: 80080005 服务器运行失败 (异常来自 HRESULT:0x80080005 (CO_E_SERVER_EXEC_FAILURE))。
VisualStudio Bootstrapper:2018/5/6 10:07:12: Download failed using Bits engine. System.Runtime.InteropServices.COMException (0x80080005): 检索 COM 类工厂中 CLSID 为 {4991D34B-80A1-4291-83B6-3328366B9097} 的组件失败，原因是出现以下错误: 80080005 服务器运行失败 (异常来自 HRESULT:0x80080005 (CO_E_SERVER_EXEC_FAILURE))。
在 Microsoft.VisualStudio.Setup.Download.Bits.BitsEngine.<>c.<.ctor>b__3_0()
在 System.Lazy`1.CreateValue()
在 System.Lazy`1.LazyInitValue()
看到该日志，原以为是我的电脑无法正常访问https://aka.ms/vs/15/release/installer，但实际经过手动下载，是可以正常快速下载的，所以排除了网络问题，在此感谢DUDU的积极回复，虽不是网络问题，但至少表现出对该事情的关心。