You can download an ext4 file system driver to view and edit the files on that partition. I don't know if a file system driver will make Bootgrabber get the correct arc path for the partition though. It doesn't matter for you though because that partition doesn't contain Windows XP. Maybe it doesn't matter to anyone if Bootgrabber only fails in the case where a filesystem doesn't exist. However, it did fail in the case of disk0 partition2 which is a valid NTFS file system; even though it's not a Windows XP partition, it is conceivable that it could have been.