ok so according to this service manual
http/h10032.www1.hp.com/ctg/Manual/c02720306.pdf p.11
you have 1 gb of dedicated video memory. this is separate from the system ram and can not be changed to system memory or system memory to more vram. if you want more system ram you will need to add more there but you can't add to the vram from what i am seeing. same page says there is an 8gb limit to the 2 ram slots on the laptop.
this is why you don't see any settings for it since you can't change dedicated ram to something else. if you are not sure what ram you would need i like the scanning tool at crucial.com. it will scan the laptop and see what is installed now and what can be added. you don't have to buy from them but it will let you know what is compatible. basically it is up to ddr3-1333 2x4gb set.