# Could not find the main class: org.elasticsearch.bootstrap.Elasticsearch

**URL:** https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218
**Category:** Elasticsearch
**Created:** [May 28, 2016, 10:25am UTC](https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218 "2016-05-28T10:25:02Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![yoavb](https://avatars.discourse-cdn.com/v4/letter/y/839c29/32.png) [@yoavb](https://discuss.elastic.co/u/yoavb)
#### Post date: [May 28, 2016, 10:25am UTC](https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218/1 "2016-05-28T10:25:02Z")

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Hello ,  
I have download Elasticsearch 2.3.3 and tried to install it on my laptop Windows7 - 64bit.

C:\Elastic\elasticsearch-2.3.3\bin\>java -version  
java version "1.7.0\_80"  
Java(TM) SE Runtime Environment (build 1.7.0\_80-b15)  
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)

I am getting the following error message  
C:\Elastic\elasticsearch-2.3.3\bin\>elasticsearch.bat  
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/elasticse  
arch/bootstrap/Elasticsearch : Unsupported major.minor version 51.0  
at java.lang.ClassLoader.defineClass1(Native Method)  
at java.lang.ClassLoader.defineClassCond(Unknown Source)  
at java.lang.ClassLoader.defineClass(Unknown Source)  
at java.security.SecureClassLoader.defineClass(Unknown Source)  
at java.net.URLClassLoader.defineClass(Unknown Source)  
at java.net.URLClassLoader.access$000(Unknown Source)  
at java.net.URLClassLoader$1.run(Unknown Source)  
at java.security.AccessController.doPrivileged(Native Method)  
at java.net.URLClassLoader.findClass(Unknown Source)  
at java.lang.ClassLoader.loadClass(Unknown Source)  
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)  
at java.lang.ClassLoader.loadClass(Unknown Source)  
Could not find the main class: org.elasticsearch.bootstrap.Elasticsearch. Progr  
am will exit.

Please advise

Thanks  
Yoav

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### Author: ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)
#### Post date: [May 28, 2016, 11:36am UTC](https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218/2 "2016-05-28T11:36:12Z")

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Probably your `JAVA_HOME` is wrongly set and points to a java version 1.6 ?

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### Author: ![yoavb](https://avatars.discourse-cdn.com/v4/letter/y/839c29/32.png) [@yoavb](https://discuss.elastic.co/u/yoavb)
#### Post date: [May 28, 2016, 11:43am UTC](https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218/3 "2016-05-28T11:43:17Z")

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Yep .....

C:\Users\yoavb\>set JAVA\_HOME=C:\Program Files\Java\jre7

C:\Users\yoavb\>cd C:\Elastic\elasticsearch-2.3.3\bin

.... Succsessfully installed and started .

Thanks  
Yoav

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### Author: ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 5, 2017, 10:48pm UTC](https://discuss.elastic.co/t/could-not-find-the-main-class-org-elasticsearch-bootstrap-elasticsearch/51218/4 "2017-07-05T22:48:21Z")

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