1.
Download Java SE JDK (Java SE <version>, JDK Download), and install.
Windows x86 = for 32-bit Windows
Windows x64 = for 64-bit Windows
(To check 32-bit or 64-bit on Windows 7, Start menu >> Computer >>> Right-Click >> Properties; for Windows 8, go control panel, systems)
Right-Click >> jdk*.exe >> Run as administrator
2.
Windows 7, Windows Explorer
Organize >> Layout >> (check) Menu bar
Tools >> Folder Options >> View >> (uncheck) Hide extensions for known file types
Windos 8, Windows Explorer
View >> Options >> Change folder ... >> View
3.
Download Notepad++, and install.
4.
Windows 7
Start menu >> Computer >>> Right-Click >> Properties >> Advanced System Settings (for Windows 8, control panel >> systems >> Advanced System Settings)
>> Environment Variables (Advanced Tab)
>> User variables /
Temp >> System Variables / Path >> Edit
>> append this to the back (check your program files directory for the correct path, no space before/after ;)>> ;C:\Program Files\Java\jdk1.7.0_10\bin
(copy path of bin directory of JDK, Windows Explorer > program files > Java ... > Bin, copy address as text)
5. Go to command prompttemm
Start menu >> type "cmd"
type "javac"
You should see some javac command output (not error message)