How can i create Logical partition from my harddisk

My HDD have 4 Primary partition. It still i have 280GB unallocated space but i can't create partitions. I need two more partitions. When i am going to make partition it show me a message like "Disk will be converted to Dynamic". I know in win7 x64 its not possible to make more than 4 Primary partition, but i need to create Logical don't need primary. Here i have attached a picture of my disks, where yellow marked drives are my PC'S internal hard disk condition: So, please help me. I have tried about 4 days but have failed and i have exam soon. So, please help me as early as possible.

Minitool Partition Wizard can convert from Primary to Logical.
MiniTool Partition Wizard Free Edition 9

You should backup your data BEFORE making changes so you can recover if something goes wrong.
It looks like you have plenty of free space on your Disk 2 [I] partition to create backups.

Instructions to convert from Primary to Logical are here:
Set Partition as Logical

If i had your setup, I would convert [F] to logical.

hth, de

Thanks a lot...