Advice on Increasing VRAM

[Dusty Graphics Card]

So I have an Asus S500CA laptop.
Here are the specs:
Intel Core i5-3317U CPU @ 1.70 GHz 1.70GHz
12.0 GB RAM (11.8 Usable)
64 bit
Intel HD Graphics 4000
Total Available Graphics Memory: 1824 MB
Dedicated VRAM: 128 MB (Originally 64 MB before I increased it)

So my question is that what will happen if I increase VRAM?
How do I check if VRAM has been successfully increased?
Are there any downsides?
What does VRAM even do?
Thanks!

 

[basroil]

Completely pointless to do that in Win 7 and up. All it does is reserve 128MB of system RAM at the bios level for your internal graphics, so your maximum system memory ends up being 12.0GB - 128MB. For the HD4000 on Win 7 and up and that much RAM, it does absolutely nothing beneficial or detrimental except in edge cases I'm sure have nothing to do with you