Update Ubuntu to 11.04

Update Ubuntu to 11.04

After I updated my operation system to ubuntu11.04, I could not login my system again.

So I tried some way to fix my computer.

1. try to show the GRUB menu
boot the system from the disk, get the terminal console.
>su root
>grub
>root (hdx,y)
>setup (hd0)
>quit

2. try to login the system, my problem is caused from the video card driver or something.
I reinstalled my video card driver.

>sudo apt-get install unity-2d
>sudo apt-get install compizconfig-settings-manager

references:
http://wowubuntu.com/natty-faq.html