What is the recommended Java for a W10 OH Installation?

I’m running OH 2.3 on a Windows 10 PC. In the past I experienced problems with Oracle newer JAVA releases and settled on the 32bit of release 8.171 .

I’m planing now the upgrade to OH 2.4 so my question is it recommended to upgrade the JAVA as well pr should I remain with 171?

If that JAVA version worked for you there is no direct need to update. (or if there are some minor upgrades for your JAVA 8 version you can update). The next version wil supported will probably be JAVA 11, but there are some issues. So for now it’s JAVA 8. I assume if something changes with version this will be in the release notes of a next openHAB version.