Partition Magic 8 can access the other primary Windows partition for you, but it isn't free though. I think there's a trial version. http://www.softpedia.com/get/System/...on-Magic.shtml
You can use ERD commander, but M$ just bought them, and there's no more evaluation out.
(free solution) You can use Knoppix, but it requires some skill getting NTFS write support. Another way is to format the 2nd XP partition as FAT32, boot into Knoppix live CD, edit the fstab file, mount the 1st XP partition, locate your files, copy it into the FAT32 partition. Then format the 1st XP partition as FAT32 also and reinstall Windows. Boot back into Knoppix live CD, copy the file from the 2nd FAT32 partition back to the 1st partition. Once you are done boot back into XP, and open up command prompt and type convert drive_letter: /fs:ntfs to make it NTFS again.
drive_letter being c: usually
convert c: /fs: ntfs
(free solution) Try using Gparted, I don't know if it has the feature to transfer file between two primary NTFS partitions like PM8 though. http://gparted.sourceforge.net/screenshots.php
There's probably an easier way, but just can't think of it right now.