ext2/ext3 from windows:
windows from Linux (if ntfs-3g is not installed yet):
- sudo apt-get install ntfs-3g
- edit /etc/fstab, replacing the "ntfs" in the line that identifies the windows partition with "ntfs-3g". (You may still be denied writing permission in spite of using ntfs-3g but that can easily be solved.)
- remount the windows partition: sudo mount -o remount /dev/sd? (check /etc/fstab or use sudo fdisk-l to determine the specific number that represents your windows partition and substitute it for the ?).