Formating wont increase your performance, but you can defrag your disk. The best discdefragger i know is perfectdisk. Its shareware (15 trials days). If you really want to turn your HD in a new one use zerofill, however there is a big chance to damage it permantly, not recommended.
i know it's deleting all data , lol
how can zerofill damage my hard disc?
do you know more programs which increase the performance?
and last question ^^ what to do first ? format and then Def or Def and then Format?