Please, what are the steps involves in setting java classpath variables in order to compile .java file to .class file.

Honestly speaking, you dont wanna mess with your environment variables. Just install the JRE and JDK and compile.

Its stil not a good idea for a beginner to start messing around with stuffs(environment variables) he doesn't even understand. God knows how many systems(frm my course mates) I have had to fix because they messed with those variables. A simple install of the JRE and JDK is enough for compiling java source files.

However, if your system is not satisfied with that, then there are lot of thing to consider. Some systems use Program Files(x86) and some use Program Files as the directory for Java. Thats just the most common one and if you look at the link you posted, it uses Program Files. You can also see cases where the system has multiple versions of Java installed.

These small things must be taken into consideration and in most cases you only see people asking such questions when they have read some article and messed with their environment variables and then unable to fix it.

Well you are right! But do you really want to be held responsible for 'damaging' someone's computer?, And to worsen the case, you cant see it(the computer) physically so fixing it is a pain!

HAhahahahahahahahhahahahahhahahah lmfaoooooo!!!!!!!!