is the video card upgradable? I installed games but it doesn't run.
No. Like all Atom-based netbooks, the graphics processor is soldered on the board.
The x120 uses an Intel GMA950 video controller.
Currently the Atom-based systems with nVidia ION video controllers are much faster for video. This is not available on x120 netbooks.
You can check with LG and get an upgrade for it.