OK you realize
normally to update GPU on most laptops requires tearing almost the entire computer apart? That is if you can.
First place to start looking is the manual/guide
http://support.acer.com/acerpanam/Manuals/acer/2009/ServiceGuides/SG_Aspire_5517_09172009.pdf
I am looking through it, and I don't see any reference to a GPU.
Just looking at the picture of the motherboard tells me it is integrated, impossible to replace. Sorry but the onlyway that GPU is getting updated is with a new motherboard/computer
When looking for parts for laptops, its better to look through the parts that fit the computer, not look for parts, then see if it fits the computer.