I get an error when I try to start STS.

When I start STS, I get the following error:
What should I do?

A Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available in order to run STS. No Java virtual machine was found after searching the following locations: C:\STS\sts-bundle\sts-3.9.6.RELEASE\jre\bin\javaw.exe /present