Windows 7: hard disk lost space

i bought a samsung 1000 gb hdd. model:HD103SJ (1000GB/7200rpm/32M) it was my primary hdd. when i bought it, had 938GB total space... i formatted n pertitioned it couple times... last time when i broke all pertition then it showed total 931. something... so total more than 7 gigs r completely vanished.... i tried to find that space but as i said, completely vanished..... so pertitioned it again with 931 gigs...... now how can i regain that 7 gigs????? plzzz help guys..........

harddrive becomes smaler and smaler over time.
when you format a HD or check it for errors.. bad sectors are marked as unusable and are not used by filesystems.
those bad sectors can't be repaired, they are vanished indeed.

but however 7 GB is alot.
how old is your HD?

1.5 years maybe... but it made in china... and i always checked for errors n bad sectors n cleaned all.... n defraged almost every week.... and i havent seen any unusable bad sectors.... it always worked pretty good... still working as a secondary by a RAID to USB on my laptop... but lost that 7gigs... plzzz help... i only loaded 500 gigs on total 6 drives... C drive is empty.... coz um not using dat pc nymor my asus eee pc runs on win xp sp3 32bit.. but if that hdd keeps on shrinkin, i'll lost all 500 gigs of hardwork..... help plzzz