Thanks for the hints.

Yes I gone through it but I did not get the clue it seems. When I set the type, nothing happens. I come back to the screen and it still says /dev/ hda3 | Linux|[empty]| size.
And it says for the other partitions swap for hda1 and ext3 for hda2 where it is empty for the third partition.

I think I will not need more than the 2,5 GB because I do not need something like open office because the only purpose will be a file server for linux clients and a samba for backup or so.

McGyver