1. During the installation of jdk, two installation prompts will appear. The first time is to install jdk, and the second time is to install jre. It is recommended to install both in different folders within the same java folder. (They cannot both be installed in the root directory of the java folder. An error will occur if jdk and jre are installed in the same folder), as shown in the figure below:

2. Install jdk, choose the directory at will, just modify the directory before the default installation directory java; install jre → change → the directory before java and the directory where jdk is installed can be the same;

Note: If there is no installation directory requirement, all default settings can be used. There is no need to make any modifications, just click Next twice.

3. After installing jdk, configure environment variables: Computer → Properties → Advanced System Settings → Advanced → Environment Variables;

4. System variables → Create new JAVA_HOME variable.

The variable value fills in the installation directory of jdk (I am E: Javajdk1.7.0).

System variables → Find Path variable → Edit, enter %JAVA_HOME%bin;%JAVA_HOME%jrebin; at the end of the variable value.

(Pay attention to whether there is a ; sign at the end of the original Path variable value. If not, enter the ; sign first and then enter the above code)

5. System variables → Create new CLASSPATH variable;

Fill in the variable value .;%JAVA_HOME%lib;%JAVA_HOME%libtools.jar (note the dot at the front);

System variables are configured.

6. Check whether the configuration is successful, run cmd and enter java -version (there is a space between java and -version);

If the version information is displayed as shown in the figure, the installation and configuration are successful.

The above is the process of installing jdk and configuring environment variables in the Windows 7 system environment. If you need to use jdk and set environment variables when using your computer, you can use the above method to install and set up.