typical path problem dude!! if u open a console & set the PATH variable...bingo!

u r done!! but i think when u exit form that console...setting will gone!!
so u need to fix this up permanently...
RClick on mycomputer > properties > advanced > environment variables > user variable/system variable section's NEW button > it'll ask for 'variable name' & 'value'
set 'variable name' to PATH & it's value to the java's 'bin' directory...save the changes...u r done!