you can buy from a PC shop it's that simple.
yes but too slow it also not run gamz require 128mb video memory
There is no 4X AGP Graphics card that has 256MB but only 128MB that's called the Nvidia Geforce4 Ti4600
you can find a 256mb video card for around 20-30$
No, you can't. Laptops have its own ports. If you want to upgrade your laptop video card, you need to make sure that your laptop has proper ports (mini PCI-E). And then get a video card which will fit that port.
You can upgrade an AGP video card to any other AGP video card.
7200GS is old. If you want to upgrade right now. I recommend you to get something better. For example: 9600GT. Good power. Not too expensive, not a lot of power consumption.
SEEK 128mb Video cards on EBAY :D
I would suggest you go for the 2gb ram and 512mb vcard. It has more performance. 2gb can run Vista and windows 7, while 128mb vcard you'll have trouble on running on these current systems. 128mb vcard is not worth it for a 3gb RAM nowadays. unless its a ddr3 and supports cuda and other nvidia or ati stuff, which is impossible on today's tech. Also, if need be, you can upgrade the RAM from a 2GB to more. It's harder to upgrade a GPU, and more expensive as well.
normally i would say the 512mb but it depends on the price and quality
there is no advantage actually the exact oppisite. you dont have to worry about matching when you only have one ram card instead of 2
most likely, yes
You can upgrade/update your 'Graphic Card' on ANY laptop or computer 'Video Card' = 'Graphic Card' Search 'Video Card' for more help.