windows 7 - Create NTFS partition for files for dual boot Win 7 (3 primary partitions) & Debian

My problem is that I want to partition my disk so there is no conflict between debian & win 7 AND that they can both access my files.
I have a 1 TB hard disk. I installed Windows first, it created automatically 3 partitions :

• SYSTEM, about 100 MB


• A disk Image for recovery purposes, 15 GB


• The main C: partition with the rest

I then reduced the size of C: to 100 GB and started the installation of Debian (I'm not a pro user). I reached the partitioning part and now I have a problem : It writes that the 3 partitions created by Windows are primary partitions, but I searched the internet & tried : there can be only 4 primary partitions... and Windows can't read "logical partitions" (LVM).

I wanted to add 3 partitions in the free space :

• One for the linux root, 20 GB


• One for the swap (18 GB)


• And all the rest (more than 800 GB) for the shared NTFS partition

Now I'm wondering how to achieve this. Is it possible to merge some partitions without troubles ? I just want to be able to write or read in a directory, no matter which OS I use.

The best I had looked like this :

• Primary, 105 MB, NTFS (SYSTEM created by Windows)


• Primary, 107.4 GB, NTFS ( resized C: partition )


• Logical, 20 GB, EXT4, mount for /


• Logical, 18 GB, swap


• Logical, 850 GB, EXT4 (Shared space, but logical & EXT4)


• Primary, 15 GB, NTFS (Recovery Image)

Thanks for all help.

Answer

Finally I was able to remove the System partition and merge it to the windows ( C: ) partition during a clean installation. The system primary partition do not have to be appart from the Windows partition, be it's set like this by default.

To achieve it, there should be a partition already created before the windows install. (If there's no partition, the installator creates one for System, one for Windows ; if there is already a partition, both go on that partition).
I can't link to a particular article, but I searched for "remove System partition" and it can be helpfull.

The next part was simple because i had one new primary slot : everything was primary (except the logical swap & debian)