You can uninstall the JRE by using either the Java Removal Tool or the Java Uninstall tool.
To uninstall the JRE, with the Java Removal Tool, use the Add/Remove Programs utility in the Microsoft Windows Control Panel. The Java Removal Tool is integrated with the uninstallation process, and it will guide you through the removal of older JREs.
To uninstall the JRE, with the online Java Uninstall tool, go to https://www.java.com/en/download/uninstallapplet.jsp
The Java Uninstall tool helps you improve your computer security by finding and uninstalling older versions of Java. The Uninstall tool shows you a list of the Java versions on your computer and then removes those that are out-of-date.
Note:
The Java Uninstall tool will not run if your system administrator specified a deployment rule set in your organization.
The deployment rule set enables enterprises to directly manage their Java desktop environment and continue using legacy business applications in an environment of ever-tightening Java applet and Java Web Start application security policies. The deployment rule set enables administrators to specify rules for applets and Java Web Start applications. These rules might specify that a specific JRE version must be used. Consequently, the Java Uninstall tool will not run if it detects a deployment rule set that ensures required JREs are not uninstalled.
See Deployment Rule Set in the Java Platform, Standard Edition Deployment Guide.