Tip - MSXML可能导致.net framework 3.5 sp1安装失败

今天的一个客户支持案例：安装.net framework 3.5 sp1不成功，安装日志信息：

dd_dotnetfx35error.txt有一条如下：

Installation failed for component Microsoft .NET Framework 3.5 'package'. MSI returned error code 1603

搜索到一篇blog 提到可能是MSXML的注册表信息损坏导致，可检查dd_NET_Framework35_MSI*.txt中是否有如下信息：

MSI (s) (48:74) [10:41:04:968]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI14D.tmp, Entrypoint: ExecXmlConfig
MSI (s) (48:3C) [10:41:04:968]: Generating random cookie.
MSI (s) (48:3C) [10:41:04:984]: Created Custom Action Server with PID 3032 (0xBD8).
MSI (s) (48:E8) [10:41:05:015]: Running as a service.
MSI (s) (48:E8) [10:41:05:015]: Hello, I'm your 32bit Elevated custom action server.
ExecXmlConfig: Error 0x80040111: failed to load XML file: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG\web_mediumtrust.config
MSI (s) (48!9C) [10:41:05:093]: 产品: Microsoft .NET Framework 3.5 SP1 -- Error 25541.Failed to open XML file C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG\web_mediumtrust.config, system error: -2147221231

解决方案：

1.命令行运行以下这个命令：regsvr32 msxml3.dll

或者下载http://www.microsoft.com/downloads/details.aspx?familyid=28494391-052b-42ff-9674-f752bdca9582&displaylang=en 后安装一下

2． 电脑重启 (建议)

3． 安装.net framework 3.5 sp1