Lost Data

hello, i need someone's help with recoverying my data from an external harddrive..
It was working fine until 2days back when i connected it onto my laptop and it could not be accessed and when i checked its properties,it showed me "0 bytes". have tried to recover the information using "Get data back tool, Recover My Files tool" but still in vain... someone please help... if there are any stronger recovery softwares or harware machine that can be used to get my data back..
Thanks..