Now it is time to partition your disks. First you will be given the opportunity to automatically partition either an entire drive, or free space on a drive. This is recommended for new users or anyone in a hurry, but if you do not want to autopartition, choose manual from the menu.
If you have an existing DOS or Windows partition that you want to preserve, be very careful with automatic partitioning. If you choose manual partitioning, you can use the installer to resize existing FAT or NTFS partitions to create room for the Ubuntu install: simply select the partition and specify its new size.
If you want to customize the partition layout, choose Manually edit partition table from the menu, and the next screen will show you your partition table, how the partitions will be formatted, and where they will be mounted. Select a partition to modify or delete it. Remember to assign at least one partition for swap space and to mount a partition on /. Appendix C, Partitioning for Ubuntu has more information about partitioning.
Manual-t választva, kiválasztod a particiót, majd onnantól az automatikusan beállított értékekkel lehet dolgozni. Én hibám..:)