richard.g

i recently purchased a asus laptop computer the specs are 250 gb harddrive 2.0 ghz intel centrino core2 prossecesor , 4 gb ram, vista 64bit but i noticed when i got home that when i looked in computer it only read that i have 222gb so i took it back to bestbuy and they said that windows was using the rest for the operating system so i left it at that but was still a little skeptable so as i got a little more familure with vista i got to looking around and went to disk management and noticed that my harddrive is partitioned and windows is only using 10.74gb and my total harddrive space is 232.88 so that started my curiousity back up because im missing 17.12 gb i have an external harddrive that i know is 120gb and when i plug it in it only reads as 111 so i did a little research and came across a program called treesize and run that and it says i have 152 free of 222 and says im using 56 gb on my harddrive right now so where is the other 14 gb is there something i dont know about harddrive space or could i have gotten a bad harddrive
one more thing in disk management it says my disks are healthy