It is necessary to have Java for OpenRocket to work.  Most computers already have it.  It’s free.   You can download Java using Safari on a Mac or Microsoft Explorer, so open one of those. (On a PC, you may have to do a search for Explorer.  Note that the “e” icons for Edge and Explorer look very similar.)  Neither Microsoft Edge nor Chrome will work.

 

1.  Go to Google.com and type in “Java”.  Click on “Java/Oracle”, it should be first on the list. 

 

2.  Click on “Java Download”

 

3.  Click “Agree and Start Free Download”

 

4.  If it asks, “Do you want to run or save?”  Click “Save” and wait.

 

5.  Now, you may have to find the Java app (especially on a Mac) and double click it, but a new window may open automatically. 

 

6.  In the new window, click “Run”.  This will install the download.

 

7.  After some time, a new window will appear that says, “You have successfully installed Java”. Click “Close”.