I just did a simple google search on your laptop and it brought up very specific specs about your laptop, using this information I'm sure you can find out if this is a laptop that's upgradable as far as graphics:http://support.acer.com/acerpanam/notebook/0000/Acer/Aspire6930/Aspire6930sp2.shtml
I'll post back if I learn anything else.
*Edit: Does your laptop have an actual card in it? Or, is it a built in graphics card? If it has an NVIDIA card or anything of the sort, then it is upgradable. If it has the Mobile Intel GM45 Express Chipset, then I do not believe it is upgradable.
Hope this helps.