Remember once jdk configuration issues

Before learning java with Eclipse when configured shining on the book in one hand and jdk, after such a lapse of six months, to be replaced because the idea (a novice, yet nothing will), someone sent me with a .java and html the project has not been molding and other documents, and then found not run after opening, felt the need to configure single-handedly maven, then the configuration found during his jdk problems, enter java, java -version no problem under cmd, and then javac display : 'javac' is not an internal or external command, operable program or batch file. Internet search a lot of shining changed and it did not work. Finally, gas, but uninstalled jdk, re-download the latest version of a jdk1.8, and then found that java, javac, java -version displays are a problem: Error: could not `Open E: \ Program Files \ the Java \ jre7 \ lib \ amd64 \ jvm.cfg '. Then even more it collapsed. See other people said it might be because in the c: / windows / system32, need to delete java.exe, javaw.exe, javaws.exe these three documents, but I can not find three files in this directory. Then turn to a related article posted about the link; https://blog.csdn.net/WJWFighting/article/details/81077839. Everything down as he said to the three path name contains \ Oracle \ path of words java \ javapath deleted files, files again all other versions of these three file names deleted, or not, but this time have become: 'javac' is not an internal or external command, operable program or batch file. Then I put C: \ ProgramData \ Oracle \ Java \ java.exe javaw.exe javapath in, javaws.exe gave deleted this time I thought of and control over the book a bit, then found himself to be in Path system variable is set there, set up user variables, the first time such a configuration is certainly not a mistake, it is time for me in unloading heavy equipment jdk, environmental configuration, careless with the wrong location. All in all, somehow, the next step is to continue configuring the maven environment.