So, I installed a brand-new Windows 2019 server where I wanted to install Azure AD Connect version 2.x. Or better, I wanted to upgrade an existing Azure AD Connect version 1.x server to version 2.x. After starting I got the following error message:

This installation requires TLS 1.2, but it was not enabled on the server. Please refer to this document to learn more about the steps you need to take to enable TLS 1.2 on your server. After configuring TLS 1.2, please run AADConnect Wizard to continue with installation and configuration.

Luckily it’s not that difficult to enable TLS 1.2 on a Windows 2019 server (although I am wondering why this is not enabled by default) by using the following registry keys:

[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:0000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SystemDefaultTlsVersions"=dword:00000001
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server]
"Enabled"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server]
"DisabledByDefault"=dword:00000000

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client]
"Enabled"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client]
"DisabledByDefault"=dword:00000000

To easiest way to get these on your server is by using the following PowerShell commands:

New-Item 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319' -Force

New-ItemProperty -path 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319' -name 'SystemDefaultTlsVersions' -value '1' -PropertyType 'DWord' -Force

New-ItemProperty -path 'HKLM:\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319' -name 'SchUseStrongCrypto' -value '1' -PropertyType 'DWord' -Force

New-Item 'HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319' -Force

New-ItemProperty -path 'HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319' -name 'SystemDefaultTlsVersions' -value '1' -PropertyType 'DWord' -Force

New-ItemProperty -path 'HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319' -name 'SchUseStrongCrypto' -value '1' -PropertyType 'DWord' -Force

New-Item 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server' -Force

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server' -name 'Enabled' -value '1' -PropertyType 'DWord'

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server' -name 'DisabledByDefault' -value 0 -PropertyType 'DWord' -Force

New-Item 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client' -Force

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client' -name 'Enabled' -value '1' -PropertyType 'DWord' -Force

New-ItemProperty -path 'HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client' -name 'DisabledByDefault' -value 0 -PropertyType 'DWord' -Force

Note. You can add | out-null to each command to suppress the console output

After running these commands, Azure AD Connect was installed as expected.