萨米金人，

感谢您在MSDN论坛中发帖.

Thank you for posting in MSDN forum.

我了解发生.Net Framework问题时带来的不便.

I understand how inconvenience it brings when occurring .Net Framework issue.

>>框架安装失败，错误代码:(0x80070643)，安装过程中出现致命错误"

这通常意味着安装包丢失或损坏.

It usually means that the install packages are missing or corrupted.

对于您的问题，这是我的建议:

For your question, here are my suggestions:

1.由于您创建了有关Win 7 Pro的还原点，因此请同时安装 Win 7 Sp1

1. Since you created a restore point about Win 7 Pro, please also install Win 7 Sp1

2.使用 .NET 框架设置验证工具 来验证计算机上安装的所有框架.如果有任何问题，我们可以使用 .NET Framework修复工具  进行修复.

2. Use .NET Framework Setup Verification Tool to verify all the framework which installed on your machine. if there is anything wrong about it, we could use  .NET Framework Repair Tool  to repair it.

3. Microsoft .NET Framework 4的更新4.0.3，因此请安装 Microsoft .NET Framework 4 .

3.  Update 4.0.3 for Microsoft .NET Framework 4, So please install Microsoft .NET Framework 4.

4.下载并安装 Microsoft更新4.0.3. NET Framework 4

4. Download and install Update 4.0.3 for Microsoft .NET Framework 4

如果存在任何问题，请随时告诉我，我仍将尝试分析根本原因.

If there is any problem existed, please feel free to let me know, I will still try to analyze the root cause.

***的问候，