Deleting files requires password and doesn't increase free space I've been using my Mac for around 2 years, and 3 years overall with uni. I keep deleting files. When I do this, it comes up asking me to confirm my password that would normally come up after logging out and back in.

When I go to 'Trash', there is nothing inside the folder. Then, when I check my hard drive info, it just keeps going down in size, and not back up. Even deleting files over 1 GB in size. Makes no difference. Anyone got any ideas?
google a program called Grand Perspective and run that and you can see where the files are sitting as it scans your hard drive.