Hello jdthtd and welcome to Seven Forums.
Sometimes the reason why you can't install the latest version of Adobe Flash is because a previous version hasn't been completely removed from the computer. Try using the official Adobe Flash uninstaller and then try installing the latest version (which as of today is 11.5.502.135). Don't forget to uncheck any added toolbars, browsers, etc that might be offered with the new Flash.
Uninstall Flash Player | Windows Adobe - Install Adobe Flash Player
I'm a little confused with your second problem regarding JavaScript. JavaScript is a browser-based
scripting language. It allows programmers and advertisers to create interactive web pages with pop-ups, etc on the web pages. Because it's browser-based it's not something you download in the traditional sense. To enable/disable JavaScript in Internet Explorer go to Control Panel > Internet Options > Security tab > click Custom Level button > scroll down to the Scripting section. That's where you would enable or disable JavaScript.
In Chrome, see this article;
Enable JavaScript in Google Chrome | activatejavascript.org
I'm guessing that you may have received some kind of alert that a program you were trying to run (an anti-virus program, perhaps?) needed Java (a
programming language) and not JavaScript. If this is the case, make sure all traces of any previously installed versions of Java have been removed from your computer. An effective removal tool is JavaRa. Once you run JavaRa you can get the latest version of Java.
JavaRa | SingularLabs java.com: Java + You
If I completely misunderstood your situation I apologize.