Well i have seen in many screen caps of the desktop that, at the botton of the hdd icon in the finder, u can see the use /free space on the hard disk
How can i do that...or at last..if it's obvious or in another post..please tell me the name of that "feature"

Right Click/Control Click the Desktop and Click "Show View Options"

Then its all in there

right click desktop > show view options > check "show item info"

jajaja the post title says all, STUPID question, i think that was a hidden feature in the finder or maybe a plugin....jeejje
Thanks to all!