HDD in Studio 1555-9964

Hi,

I need to know the specific hard drive model installed in my Dell Studio 1555-9964. I don't have this disk right now and I can't find the specifications of this laptop on the internet. The service code on the Dell site is not found (it's G8CP7K1).
Can you help me? Thanks.

PS sorry for the chosen board, but there is no one for Studio series.