Question

安装Microsoft .NET Framework 4.5.1出现严重错误！

这是错误日志
OS Version = 6.1.7601, SP = 1.0, Platform 2, Service Pack 1
OS Description = Windows 7 - x64 Ultimate Edition Service Pack 1

MSI = 5.0.7601.18493
Windows version = amd64_windowsfoundation_31bf3856ad364e35_6.1.7601.17514_none_615fdfe2a739474c.manifest
Windows servicing = 6.1.7601.17592

CommandLine = E:\f9ad8af03aa97497ecc9\\Setup.exe /x86 /x64 /redist

Using Simultaneous Download and Install mechanism

Operation: Repairing

Package Name = Microsoft .NET Framework 4.5.2 Setup
Package Version = 4.5.51209

User Experience Data Collection Policy: Disabled

Number of applicable items: 8

Exe (E:\f9ad8af03aa97497ecc9\SetupUtility.exe) succeeded.
Exe Log File: dd_SetupUtility.txt

Returning IDNO. INSTALLMESSAGE_USER [您必须重新启动系统才能使对 Microsoft .NET Framework 4.5.2 做出的配置更改生效。单击“是”立即重新启动；单击“否”可在以后以手动方式启动。]
MSI (E:\f9ad8af03aa97497ecc9\netfx_Full_GDR_x64.msi) Installation succeeded and requires reboot. Msi Log: Microsoft .NET Framework 4.5.2 Setup_20150621_131148305-MSI_netfx_Full_GDR_x64.msi.txt

RelatedProducts (RepairProduct) failed on product (Microsoft .NET Framework 4.5.2 (CHS)). Msi Log: Microsoft .NET Framework 4.5.2 Setup_20150621_131148305-{0D78BD21-52EC-3319-A4A6-8E56C74D93CA}-RepairProduct.txt

ServiceControl operation succeeded!

Final Result: Installation failed with error code: (0x80070643), "安装时发生严重错误 " (Elapsed time: 0 00:15:32).

Answer 1

第一个尝试 关掉杀毒软件和优化软件（也就是不要实时监控）重新安装
第二个尝试 上面的方法沿用，然后去下载.NET Framework Cleanup Tool 清理已安装的.net 重新启动计算机全新安装所需版本～
如果你安装了像007一样的解码器，卸载后再安装.net，因为它的权限保护会阻止.NET的安装 另外就是windows update 服务器在国内并不好用，有可能你没完整下载.NET，可以用离线安装包试试！

Answer 2

看看这个，按这个试试。
.NET framework 4.0安装失败怎么办
http://jingyan.baidu.com/article/00a07f3892376982d028dc2a.html