Under Win2000, My Computer -> Properties -> Advanced -> Environmental Variables
In the user variable, the current user is valid, the system variable is added
The users of all login systems are valid.
Java_home = d: /j2sdk1.4.2_03
Classpath = .; D: /J2SDK1.4.2_03/lib/tools.jar; d: /j2sdk1.4.2_03/lib/dt.jar
Last plus PATH; D: /J2SDK1.4.2_03/bin
If you go smoothly, DOS Java, Javac, Jar and other commands can be used in any directory.
