Java SE (Java Platform, Standard Edition)

Lets say i wanna write and test helloworld.java in Win Vista.

Ive always used XP where I downloaded java as usul, and in enviroment variables I put reference
to the bin catalogue. Then i went to cmd and that was it basically...

Now, I use Vista and did the same proceduer but aint getting nowhere..: (in swedish)

C:\cf>javac helloworld.java
javac �r inte ett internt kommando, externt kommando,
program eller kommandofil.

Which says it doesnt knows what javac is...

Any suggestion?, Thanks -;)