安装Microsoft .NET Framework 4.0的时候提示安装错误，这是什么原因？

OS Version = 6.1.7601, Platform 2, Service Pack 1OS Description = Windows 7 - x86 Ultimate Edition Service Pack 1CommandLine = H:尀1312c44542935605e2700339尀尀Setup.exe /x86Using Simultaneous Download and Install mechanismOperation: InstallingPackage Name = Microsoft .NET Framework 4 SetupPackage Version = 4.0.30128User Experience Data Collection Policy: AlwaysUploadedNumber of applicable items: 10Exe (H:尀1312c44542935605e2700339尀SetupUtility.exe) succeeded.Exe Log File: dd_SetupUtility.txtServiceControl operation succeeded!Exe (H:尀1312c44542935605e2700339尀Windows6.1-KB958488-v6001-x86.msu) failed with 0x80240017 - (null).Exe (H:尀1312c44542935605e2700339尀SetupUtility.exe) succeeded.Exe Log File: dd_SetupUtility.txtMSI (H:尀1312c44542935605e2700339尀netfx_Core_x86.msi) Installation failed. Msi Log: Microsoft .NET Framework 4 Setup_20140823_135921389-MSI_netfx_Core_x86.msi.txtFinal Result: Installation failed with error code: (0x80070643), "安装时发生严重错误 " (Elapsed time: 0 00:00:37).