Pascal, most, if not all, current laptops have 'generic' items :- hard disks, optical drives, RAM, Mini-PCI cards, LCD screens....
I have a laptop that is three years old; it is possible for me to update the graphics from a 16 Mb Radeon to a 32 Mb GeForce - not much choice but it can be upgraded. I've also replaced the 30Gb hdd with a 60Gb 7200RPM item, replaced the 'branded' CDROM with a 'generic' Combo drive; I can even upgrade the CPU.
Kylua, give us some more details on what you have and we can help you. 9.5mm high 2.5" drives will fit almost all modern laptops.
Andy.