My desktop divides into quadrilateral shapes/columns and system becomes hangs in some games or in some programs. I have asked this question in Yahoo answers they suggest to change the Ram and I did so but the problem continue. I have also change the motherboard some months ago.

Can you post some pictures of this phenomena?

When you changed out the MOBO, did you reinstall the software and ALL the driver?

Have you identified you graphics card and checked for updated drivers online? Post your graphic card model here and we can help find the drivers.