Many people are asking why this " Fatal error during installation (0x80070643)" error is coming while installing SSMS. Many people are struggling on this issue at the time of installing SSMS V16.5.3,and SSMSV18.0. Here I am sharing the tips to easily rectify fatal error.
Below solutions will be helpful to rectifying fatal error at the time of installation.
1. Please check is there any antivirus are running in your system like Symantec if yes disable it and retry the installation. In most of the cases antivirus are the culprit.
2. Please check system language or local language settings in control panel, System language and setup language should be same, Means if you are using Us version setup SSMS-Setup-ENU.exe then system language should be English(United state),and SSMS-Setup-FRA.exe for France.
3. Remove every trace of .NET and visual C++ from your system , Uninstall all the trace and retry the installation
4.Install the setup priority order, Install SSMS 2016 version then after try SSMS 2017.
5. Check any higher version of depending packages are installed (like ODBC drivers) if yes uninstall it and retry.
Hope this will help you to fix fatal error.