If you've searched "install Hadoop on WSL," you've probably found guides from 2020–2023, most written for WSL1 or old Hadoop 3.2/3.3.0 builds. This guide is different: it's WSL2-specific, uses the current Hadoop 3.5.x line, and includes the exact errors WSL throws that generic Linux guides don't warn you about — SSH not starting, slow HDFS I/O on the Windows filesystem, and JAVA_HOME issues. What you need before starting Windows 10 (build 19041+) or Windows 11 WSL2 enabled wi...