Problem with my graphic card

i turn on my toshiba satellite pro a100 and i get a black screen(the screen is working but its black). i tried to plug my laptop to an external monitor, i turned off the laptop restarted it and on the external monitor i see windows loading but with floating boxes, line and blurry picture. it doesnt enter windows and the screen is black.
i want to know if thats a graphic card problem because if it is i can change it (pci express).
my graphic card is Schnittstelle: PCI Express
Grafikspeicher: 256 MB
Chipentwickler: NVIDIA
Grafikchip: GeForce 7600 GO

You cannot change the graphics card in a laptop, yes its connected via PCI-E express to the chipset, but it is not a slot, it is generally a proprietary connection and a dead graphics setup in a laptop generally means a new motherboard is needed.

sorry for the post before.
what i want to know is that it wont fix the problem if i change the video card?
my video card looks just like this one but with 256mb instead of 64 like in the link
http://www.notebooksolutions.ca/zc [...] ts_id=8015

so hunter what do u advise me to do if the garantee is expired and i cant afford a new one
maybe i should show it to a professional so he can see if the motherboard or the video card is dead?

thanks hunter
one more question: from what i wrote in the first post, in your professionel opinion, how much chances there is that the video card is dead and not the motherboard?