You most likely installed the new Win 7 over your data partition rather than over the old Win 7 partition. it is important to always MAKE SURE where you are installing an OS. When installing any OS, if you choose to install over an old OS, it WILL NOT move the old installation, it will install directly in the same partition. If this is indeed what you did, you overwrote your data with the new installation. Sorry but your data will most likely be lost. Data recovery tools are only good if the old lost data has not been overwritten. it's worth trying but in your case will probably not be effective.