Step 1: Find your Oracle installation directory. My directory: D: \ app \ ling \ product \ 12.2.0 \ client_1 \ deinstall \ deinstall.bat, and then click to manage Run bat file. Wait screen appears as follows.
Step two: wait a long time, the following screen appears:
Step 3: Select that direct the Enter key
Finally, just wait on it. (A little time slightly longer!).
After unloading, the cmd window automatically turned off, it is so good to uninstall the Oracle 12C, the step was quite simple.