On basic disk, you can not create more than four primary partitions. If you need more partitions, you must convert one primary partition into extended partition that will contains logical partitions.
If data is not important, simple way is to delete one primary partition and make one extended partition. Then create many logical partitions in extended partition area.
But when data is important then you can convert this way.
- Install EaseUS Partition Master Home Edition http://download.cnet.com/EaseUS-Partition-Master-Home-Edition/3000-2248_4-10863346.html
- Right click the partition you want to convert and select Convert to logical
- They apply