I'm searched many answers that suggest me to type in cmd:
set path = "%path%;c:program files\java\jdk1.7.0\bin"
but this is WRONG!
the right solution is that you leave "set" and just type
path = %path%;c:program files\java\jdk1.7.0\bin
P/s: of course you have to replace "jdk1.7.0" folder by your current java version folder. This works well on win 7 32bit, but I think it also works on win 8 - try it!