I installed video drivers when it came to this problem, please help me solve it.

root@rootstar:~# more /var/log/nvidia-installer.log
nvidia-installer log file '/var/log/nvidia-installer.log'
creation time: Fri May 13 09:58:41 2011
installer version: 270.41.06


option status:
license pre-accepted : false
update : false
force update : false
expert : false
uninstall : false
driver info : false
precompiled interfaces : true
no ncurses color : false
query latest version : false
no questions : false
silent : false
no recursion : false
no backup : false
kernel module only : false
sanity : false
add this kernel : false
no runlevel check : false
no network : false
no ABI note : false
no RPMs : false
no kernel module : false
force SELinux : default
no X server check : false
no cc version check : false
run distro scripts : true
no nouveau check : false
run nvidia-xconfig : false
sigwinch work around : true
force tls : (not specified)
X install prefix : (not specified)
X library install path : (not specified)
X module install path : (not specified)
OpenGL install prefix : (not specified)
OpenGL install libdir : (not specified)
utility install prefix : (not specified)
utility install libdir : (not specified)
installer prefix : (not specified)
doc install prefix : (not specified)
kernel name : (not specified)
kernel include path : (not specified)
kernel source path : (not specified)
kernel output path : (not specified)
kernel install path : (not specified)
precompiled kernel interfaces path : (not specified)
precompiled kernel interfaces url : (not specified)
proc mount point : /proc
ui : (not specified)
tmpdir : /tmp
ftp mirror : ftp://download.nvidia.com
RPM file list : (not specified)
selinux chcon type : (not specified)

Using: nvidia-installer ncurses user interface
-> License accepted.
-> Installing NVIDIA driver version 270.41.06.
-> Performing CC sanity check with CC="cc".
-> Performing CC version check with CC="cc".
ERROR: Unable to find the kernel source tree for the currently running k
Please make sure you have installed the kernel source files for y
kernel and that they are properly configured; on Red Hat Linux sy
for example, be sure you have the 'kernel-source' or 'kernel-deve
l' RPM
installed. If you know the correct kernel source files are insta
you may specify the kernel source path with the '--kernel-source-
command line option.
ERROR: Installation has failed. Please see the file
'/var/log/nvidia-installer.log' for details. You may find sugges
on fixing installation problems in the README available on the Li
driver download page at www.nvidia.com.