If you have deleted your important data (on your pen drive/harddrive) by accident, do not save anything to that drive where you delete file , just leave it.
If you have deleted files from the recycle bin and you realize you needed it, do not save anything to that drive.
If you have deleted partitions by accident, do not create another partitions, just leave it blank.
Hard drives do not actually erase data or partitions. Continue reading Recover Deleted Data With This Freeware