Yesterday I update the other computer's system to Ubuntu 11.04. The result was very disappointment.
The system went to die when it rebooted. The reason behind this is the graphic card driver: NVIDIA. I download the new version NVIDIA driver for my computer, and try to reinstall the driver.
There is the other problem show up : it can't find the header file of linux kernel.
Then I use the --kernel-source-path to tell the program where the headers are.
The other problem turn out: the "nvidia.ko" can not be loaded because the kernel version doesn't match. The kernel version can be found out by command "uname -al".
The corresponding kernel header which is ending with "pae" which I don't have. Then I use aptitude to install this header and compile the nvidia driver again. Now it works.