I have a server with Ubuntu Server 12, today it stops some services and I found some comments about full disk, so I made a df -h

S.files                   Size  Used   Disp Use% 
/dev/mapper/ubuntu-root   455G   434G     0 100% /
udev                      1,7G   4,0K  1,7G   1% /dev
tmpfs                     689M   4,2M  685M   1% /run
none                      5,0M      0  5,0M   0% /run/lock
none                      1,7G      0  1,7G   0% /run/shm
/dev/sda1                 228M    51M  166M  24% /boot
overflow                  1,0M      0  1,0M   0% /tmp

Then I tried to delete some files but I made it from a windows remote computer just right clic and "delete" option on files, but HD still full. Is in Ubuntu Server any Trash file or what could be happeing?