anyway some hard drives don't really delete stuffs, i think you need special programs to delete them permantly. like your 7 gig stuffs when you delete it, the hard drive would show 7 gig less used space but the real data is still there it's just that another data would write on top of the original 7 gig space. and for the when you tries to put them in the trash can and it told you and it's too big, it saids that because that space you allocated for the trash can is too small to contain it. right click your trash can and you can change the size for it.
I am the yellow one.