If you try installing TLauncher with JDK 17, you may end up with an error saying you need to install Java 8. The solution to this problem is a bit tedious, as you need two Java versions. So I hope this guide will clear everything up 😄
This was tested on Windows 10 and Adoptium's OpenJDK.
First and foremost, uninstall any Java versions on your system including TLauncher.
Afterwards, head over to Adoptium's OpenJDK 8 Archive and download the JRE Installer for your system. While the JRE is installing, make sure that all the features except Set JAVA_HOME variable is selected.
Now install TLauncher (preferably do a fresh install). TLauncher should have no issues running and you'll be greeted with the general interface. Great!
For the next step, close TLauncher. Open Adoptium's OpenJDK 17 Archive (this is the latest available archive for me) and download the JDK Installer for your system. Select all the features for this version to be installed: Add to PATH, Associate .jar, Set JAVA_HOME variable, and JavaSoft (Oracle) registry keys.
Open up TLauncher, go to the bottom-right corner and click the settings icon -> settings. By "Selection Java:" click the Change button. Browse to the folder where you have the JDK installed. By default it should be something like: C:\Program Files\Eclipse Adoptium\jdk-17.0.1.12-hotspot. Click save and make sure it is selected by the drop-down menu. And click save one more time.
Select the version of Minecraft you want to play with and install!
I followed the exact steps but I got this error