That seems to be the solution, however I don't know what I have to change in the file /etc/fstab. I have opened the Konsole and entered sudo kwrite, and then the root password. In kWrite I have opened the file /etc/fstab. It looks like this:
# See the manpage fstab(5) for more information.
#
# <fs> <mountpoint> <type> <opts> <dump/pass>
/dev/sda6 none swap sw 0 0
/dev/sda5 / ext3 noatime 0 0
none /proc proc nosuid,noexec 0 0
none /dev/shm tmpfs nodev,nosuid,noexec 0 0
/dev/sda1 /mnt/sda1 vfat quiet,shortname=mixed,dmask=007,fmask=117,utf8,gid=6 0 0
/dev/sda2 /mnt/sda2 ntfs-3g dmask=007,fmask=117,locale=tr_TR.UTF-8,gid=6 0 0
/dev/sda3 /mnt/sda3 ntfs-3g dmask=007,fmask=117,locale=tr_TR.UTF-8,gid=6 0 0
sda1 is a small Windows recovery partition. I have read/write acces to this.
sda2 and
sda3 are my Windows partition and my Data partition, I have no read/write access to them

What do I have to change in this file?