HP DV6 3103 sl-Does not boot with new RAM

Hi,

I have a Hp Pavilion DV6 3103sl with a dual boot W7-W7,

I would want to upgrade the RAM to 8 GB and here comes the problem:

I tried to add a new  Corsair 4 GB RAM to the samsung 4 GB that is already there,it did not work,

so I thought that there was a compatibility problem coupling RAM  from different brands and

I tried to use the Corsair alone: it did not work again.

Long story short I tried two different 4 GB Corsair and 1 Kingston 4 GB 1333 Mhz 10600

I tried them alone without the samsung RAM and all three do not work with the notebook,

it continues to boot again and again OR it gives a BSOD,

What should I do? It is impossible that all the 3 banks of RAM I tried are defective...

Thanks for your help