I have already sent an e-mail to Toshiba, but they said no video card can be replaced, because the video card is simply an on-board video card of the motherboard. So I probably have to replace the entire motherboard, or buy another laptop.... both quite expensive.
That's odd. I changed the video card in an HP laptop a couple months ago and that Toshiba looks to be roughly the same age as the HP was. But looking at the site (I should have done this before ) it only has battery and memory access panels on the bottom
I think you are probably down to either a new laptop or a new motherboard. Never having changed a laptop motherboard I don't know how easy/hard it would be