Visual Studio 2019 설치 에러 해결 방법
- 클린 제거를 했는데도 설치가 안될때 
- 원인 : 설치본이 iso 파일인 경우 최신 버전 설치본을 다운 받아 설치한다 
- CD로 이동 해서 다음 명령 실행
vs_enterprise.exe --layout c:\VSLayout --add Microsoft.VisualStudio.Workload.ManagedDesktop --lang en-US 
https://docs.microsoft.com/en-us/visualstudio/install/create-an-offline-installation-of-visual-studio?view=vs-2019 
//------------------ 
//비주얼 스튜디오 클린 제거 방법들 
* 방법 1 
"C:\Program Files (x86)\Microsoft Visual Studio\Installer\resources\app\layout\InstallCleanup.exe" -i 
* 방법 2 
vs_enterprise.exe /uninstall /force 
"C:\ProgramData\Package Cache\{a60a492e-b5eb-4218-a9e6-f38d18a7dbaf}\vs_enterprise.exe" /uninstall /force 
* 방법 3 
Visual Studio Uninstaller 
https://github.com/Microsoft/VisualStudioUninstaller 
- Visual Studio 2017까지 지원 
* 방법 4 
http://rion.io/2017/02/17/resolving-installation-issues-with-visual-studio-2017/ 
vs2017=15, vs2019=16 
- 파일 삭제 
    C:\ProgramData\Microsoft\VisualStudio 
    %localappdata%\Microsoft\VisualStudio 
    %appdata%\Microsoft\VisualStudio 
- 레지스트리 삭제 
    HKLM\SOFTWARE\Microsoft\VisualStudio\16.0 
    HKLM\SOFTWARE\WoW6432Node\Microsoft\VisualStudio\16.0 
    HKCU\SOFTWARE\Microsoft\VisualStudio\16.0