Obviously your ability to restore files is going to depend on how thorough a job you did wiping everything, and what you have done since wiping the drive to attempt to get stuff back.
Lots of people "snatch defeat from the jaws of victory" by tinkering and trying stuff out, without really knowing what they were doing. Writing to the drive or saving new files onto your D: drive will put any successful restore at risk.
So any more information on what you are running (XP, Vista etc), what file system your drive D: was running (NTFS, FAT32 etc) - very likely it isn't running ANY filesystem at the moment - if the drive has been erased.
Just remember don't start "testing" and "playing" with different tools until you know what you are doing. Some tools can dig the hole deeper.
How much data was on D: that you have lost (in GB's) do you have that much free space on another drive in your PC?