GetDataBackforNTFS could recover the data easily as it does a physical disk read and reconstructs the file system. But now that you have already installed XP, you will lose some data.
I hope you have a backup. I keep telling people in this day and age, you gotta have a 1+1 backup. NO ONE can afford to download all that stuff again.
Anyway, you will now need the software + a blank HDD to store the recovered data on. Do arrange for this. And don't use your HDD anymore to avoid further overwritin on the disk.