该文件常见出现的位置

版本	位置
3.0.6920.1109(lh_tools_devdiv_	\ProgramFiles\ReferenceAssemblies\Microsoft\Framework\v3.0
3.0.6920.1109(lh_tools_devdiv_	\ProgramFiles\ReferenceAssemblies\Microsoft\Framework\v3.0
3.0.6920.1109(lh_tools_devdiv_	\ProgramFiles(x86)\ReferenceAssemblies\Microsoft\Framework\v3.0
4.0.30319.1builtby:RTMRel	\Windows\Microsoft.NET\Framework\v4.0.30319\WPF
4.0.30319.1builtby:RTMRel	\Windows\Microsoft.NET\Framework64\v4.0.30319\WPF
3.0.6920.1205(lh_tools_devdiv_	\ProgramFiles\ReferenceAssemblies\Microsoft\Framework\v3.0
3.0.6920.0(vista_rtm_wcp.06102	\ProgramFiles\ReferenceAssemblies\Microsoft\Framework\v3.0
4.0.30319.17929builtby:FX45RTM	\Windows\Microsoft.NET\Framework\v4.0.30319\WPF
3.0.6920.1205(lh_tools_devdiv_	\ProgramFiles(x86)\ReferenceAssemblies\Microsoft\Framework\v3.0
3.0.6920.1205(lh_tools_devdiv_	\ProgramFiles(x86)\ReferenceAssemblies\Microsoft\Framework\v3.0
4.0.30319.17929builtby:FX45RTM	\Windows\Microsoft.NET\Framework64\v4.0.30319\WPF
4.0.30128.1builtby:RC1Rel	\WINDOWS\Microsoft.NET\Framework\v4.0.30128\WPF
4.0.30319.1builtbyRTMRel	\Windows\Microsoft.NET\Framework\v4.0.30319\WPF
3.0.6913.0(vista_rtm_wcp.06101	\ProgramFiles\ReferenceAssemblies\Microsoft\Framework\v3.0
4.0.30319.17626builtby:FX45RCR	\Windows\Microsoft.NET\Framework\v4.0.30319\WPF

一、如果您的系统提示“没有找到system.speech.dll”或者“缺少system.speech.dll”等类似错误信息，请把system.speech.dll下载到本机
二、直接拷贝该文件到系统目录里：
　 1、Windows NT/2000系统，则复制到C:\WINNT\System32目录下。
2、Windows XP/Vista/Win7/8系统，则复制到C:\Windows\System32目录下。
三、然后打开“开始-运行-输入regsvr32 system.speech.dll”，回车即可解决错误提示！