The ASUS laptops like your model require quite a bit of disassembly to install more RAM. There is a chance you can kill the laptop in the process. There are youtube videos on the process showing it done for your model to see whats involved before you dismantle it.
If your willing to take the risk then you can. I have a ASUS laptop that can take 8GB RAM, but by which it only has 4GB RAM. I saw whats involved and realized its more work than I want to double my memory. On my model ASUS X401A the laptop has to just about be completely dismantled to free up the main board. The RAM is on the bottom side of the main board and ASUS decided not to design it with a memory access panel. If it was located on the top of the main board such as under the keyboard I probably would dig into it and bring it to 8GB, but the risk of killing the laptop is not worth the extra memory. Additionally for $279.99 I bought myself a Core i3 Dell and that has 8GB RAM, so I will keep this ASUS X401A at the 4GB that came from factory.
