I've just downloaded Elasticsearch 7.1.1 and am trying it out on Windows 10. Just today I learned that 7.0+ comes with a bundled JDK, so I decided to give it a try without setting JAVA_HOME. However, it cannot find the JDK at the directory where it actually exists:
C:\tools\elasticsearch-7.1.1\bin>dir C:\tools\elasticsearch-7.1.1\jdk
Volume in drive C is [redacted]
Volume Serial Number is [redacted]
Directory of C:\tools\elasticsearch-7.1.1\jdk
05/23/2019 02:13 PM <DIR> .
05/23/2019 02:13 PM <DIR> ..
05/23/2019 02:12 PM <DIR> bin
05/23/2019 02:12 PM <DIR> conf
05/23/2019 02:12 PM <DIR> include
05/23/2019 02:12 PM <DIR> jmods
05/23/2019 02:12 PM <DIR> legal
05/23/2019 02:12 PM <DIR> lib
05/23/2019 02:12 PM 1,217 release
1 File(s) 1,217 bytes
8 Dir(s) 643,659,010,048 bytes free
C:\tools\elasticsearch-7.1.1\bin>elasticsearch.bat
"could not find java in JAVA_HOME or bundled at C:\tools\elasticsearch-7.1.1\jdk"
C:\tools\elasticsearch-7.1.1\bin>
It does work if I set JAVA_HOME to that same jdk directory, so I'm wondering whether this may be a bug.