...myself? I bougt my laptop at USA and can not send it to producer to repair. The keyboard does not work ocationally and sometimes, the cursor jumps chaoticly when typing

I had an Averatec 5400 series model computer that I bought from WalMart. I have had troubles with it adding spaces, freezing up and eventually not booting. I am not sure why you cannot send it to the producer, but I sent mine in for warranty repair (one year limit. It probably was about a thousand dollar laptop, you bought it because of the features (large RAM, DVD burner, cool silver color) and now you are having problems with what ended up being second rate parts used for assembly. How about using a USB keyboard and disabling the other one in the system hardware settings?

just put it in trash. Or better yet run over it with your car tire.