Just got 12.04, now I don't have any icons for my folders and programs and I can't use my mouse. I'm able to navigate using the keyboard, but when I open terminal it freezes. I tried to open the update manager but it won't install any updates. I have windows 7 as a second operating system, if this will help me at all.
I see other people having the same problem. What is your video card? Maybe it is causing problems. Is your video resolution fine or is it low resolution? Did you try to login in 2D mode? Try this link, maybe it can help you solve your problem http://ubuntuforums.org/showthread.php?t=1971539