Can’t start Intellij. It says a JAVA_HOME variable need to be defined

When I try to open idea64.exe (IntelliJ IDEA 64-bit version). It occur an error :

“if you already have a 64-bit JDK installed, define a JAVA_HOME variable in Computer > System Properties > System Settings > Environment Variables

Failed to create JVM. JVM path: C:\Programs Files\JetBrains\IntelliJ IDEA 2019.1\jre64\”

Why this error occur and how can I fix it. I already have JDK and JRE version 1.8.0, and I’ve tried many ways on YouTube but can’t fix it. I would appreciate any help