Well, that's the problem with using third party software. Had you used the built in tools in Windows you would not have been able to format the system partition, but it's very possible this utility allowed you to do that by exiting Windows when you clicked on "okay" and then immediately performing the operations. I've never heard of or used that utility, so I can't be sure. But it certainly sounds as though you did indeed delete the partitions on your internal HD which caused all data to be lost.
What OS are you using? If you have an original OS cd or dvd, boot to it and let the installation routine begin just to see if it recognizes an existing Windows installation. I AM NOT SUGGESTING YOU PROCEED WITH A NEW INSTALLATION AT THIS TIME - you just want to see if there is an existing installation or if you did indeed delete everything.