Begging for information

Hello everybody,
My smartphone is an Acer liquid metal 120. I have rooted it. I din't have much internal memory, so I made a partition EX2 in my sd card.

I can send my apps towards this partition with Link2SD but I still have a problem...

I had many photos and music in my sd card before I chose to make a partition. So, I transferred all to my PC (windows 7).

Now, I try to transfer them again to my sd card (to the EXT2 which is not visible) but they take place in the small partition (500 mo) of my sd card...

I use Airdroid for more facility.

I would like to know how can I do for choosing the good place in my EXT2 (15.5 go).

Please, forgive my for my mistakes and if I am not in the good category.

Regards

Martein