iPhone "Restore Failed"

Recently my iPhone has not been connecting to my Mac, so I backed up the phone on to another computer to save all the information so I could restore the phone after I had renewed software. I did this and now iTunes is having probelems restoring my iPhone back to its original state.
I get through all the restore process and the phone restarts. Then iTunes displays two options: start as new or restore from (old phone). I choose the second option and the process begins. A minute or two into the process iTunes says the phone was disconnected and the restore failed. Now the phone was not unplugged. I have tried this over and over again for three days! No progress. Every time the same message. I NEED my old phone back! Do you have a solution? Thank you!