I was wondering whats the highest video card i can fit in my 15.4 inch laptop. Its a hp dv6775us and it has a 8400GS not bad but i want something a little bit better. I want to know the best i can put in my computer thank you

Don't. Simple as that.

Fitting cards in laptops is practically impossible and there are countless problems associated with it, what you have isn't bad, so stick with it.

Actually, laptop graphics chips are built right into the motherboard 99% of the time, so there's no way you could replace it. Not to mention that graphics "cards" are not sold separately for laptops, for the reasons I mentioned earlier. It wouldn't be possible anyway, as opposed to desktops, the interfaces are quite non-standard and opening up a laptop is simply madness.

It is possible on a few models, but some of the time it just results in making your laptop a static PC.

No, in most cases it's not technologically possible at all.

There WAS a small push with "upgradeable" graphics cards a few years ago. I last remember seeing them on Alienwares, and they sold upgrades. However, it's still a bad idea/not possible, as even if you DID have an actual card for the system, there's basically no chance you'd have beefy enough power or cooling to run the thing.

Isn't the 8400 a dedicated card for laptops?

It's probably possible that you could take it out, but I don't think you'll be able to find something that will take it's place.

Even if it's dedicated, most of the time to save space, even dedicated GPUs are attached directly to the PCB.

Think about how big a normal graphics card is, would that really fit into a laptop with space for the rest? Everything in a laptop is smaller than what you'd find in a normal PC, CD drive, hard drive, motherboard, etc etc.

It's a dedicated graphics chip, which means it functions completely on its own, rather than being built into the chipset or using system RAM for video memory.

In other words, i was right, don't do it.

i guess no upgrade for me :-(

you can always start saving for a better gaming notebook though (8400GS is not bad).

There's a nice group of notebooks that come equipped with a 9-series GeForce (9600M GT , 9800M GTS etc)