so i load Portal 2, click single play new game. It loads, but then i goes black except for the sub titles and it plays the audio. and i can move around, like i jump i hear chell jump, but there is no video. what do i do and has anyone else exsperiensed this? plz help

-Gamer Girl Out

PS-
i have an Acer One Aspire, 10.1 screen, 1 GB DDR3 Memory.

1 GB Ram seems to be too small but it might work.

Have you tried validating your game cache yet?