I wouldn't recommend using another partition on the hard drive to backup, especially if you'll be reformatting. Do you have another computer that's hooked up to your home network? Try using the Samba network program on your LiveCD and copy and paste all your data to another computer's hard drive through the network. Or disconnect the other computer's hard drive and plug it into yours as a slave drive, copying over all your files to it. I once had to use Knoppix to reformat, and based on my experiences, I would recommend the network option over the slave drive method, since for some reason the version of Knoppix I used didn't have native support for writing to NTFS partitions, yet the Samba network program could copy and paste all my files to the other computer's NTFS partition. Strange indeed.
Of course, if you can read from the drive, you can always burn CDs or DVDs for backups. It would take many DVDs, and even more CDs, but it could be done. You may want to omit the porn though if you choose this method.