I have installed Ubuntu 12.10 on my desktop. (Pentium 4, 80 GB hard disk, 2 GB RAM, 32-bit CPU.) And I have installed Windows XP. I made a 40 GB partition for windows and 40 GB for Ubuntu. I installed Ubuntu and it said "installation is complete" and asked me to restart. I restarted the PC and logged in. After 1 minute I get a message like this: The application compiz has closed unexpectedly. Then I closed it. After that it just stays in blank screen nothing shows up. What should I do?