TLS 1.3 on Windows Server after inplace Upgrade

23 September 2021

I upgraded my Windows server from 2016 to 2022. One of the reasons was to get support for TLS 1.3

After the painless in-place upgrade process I tested my web sites and still didn't get any TLS 1.3 connections even though I knew it was possible and I tested it on a fresh install of Server 2022.

Previously I did some extensive changes to the TLS protocols and ciphers to disable TLS 1.0 and 1.1 among other things.

I used the tool IISCrypt rather than editing the registry directly. But it doesn't support Server 2022 with TLS 1.3 yet.

Most related settings are in the registry at:


on a fresh server all the sub-keys are empty, meaning some defaults are used. But on mine, I had many ciphers, hashes and protocols disabled.

Also the keys for TLS 1.3 were missing completely, so I added them:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.3]

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.3\Client]

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.3\Server]

but I still did not get any 1.3 connections.

Next I removed all the sub-keys and values under SCHANNEL, but that didn't help either.

I found a key: Functions under


that lists all available cipher suites, but doesn't seem to reflect the order of them.

It turned out Microsoft only supports two cipher suites with TLS 1.3:


both of which I had disabled for some reason.

To see your cipther suites use:

Get-TlsCipherSuite | ft Name

I enabled them in IISCrypt and moved them to the top and after another reboot I finally had TLS 1.3 connections.

There is also a PowerShell cmdlet Enable-TlsCipherSuite which allows us to enable and sort cipher suites, I will use that next time.

I now get many of the following events (36874) in the System event log:

An TLS 1.2 connection request was received from a remote client application, 
but none of the cipher suites supported by the client application are supported by the server. 
The TLS connection request has failed.

so some client, most likely a minor search bot failed to connect, I don't think I can find out when cipher suites it supported.

It may actaully be myself by using sslyze.exe or to check my sites, those tools will try all kind of cipher suites.

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