Install VirtualBox Addons inside CentOS Guest

I have to admit that this link helped me out with this.

First you need to install GCC and the kernel sources.

su

Now type your Super User password or Root password.
yum install -y gcc
yum install -y kernel sources kernel-devel
Then we must create a symbolic link to the kernel source:
ln -s /usr/src/kernels/2.6.18-194.17.1.el5-i686/ /usr/src/linux

After this reboot the machine with the reboot command as shown below:

reboot

Once the machine has come back online we can use any one of the command shown below as per our architecture:

sh VBoxLinuxAdditions-x86.run
or
sh VBoxLinuxAddtions-amd64.run


After this reboot the machine with the reboot command as shown below:

reboot

After the reboot you should be able to move the mouse between the VM and you Host OS without hitting right CTRL key.  There is one trouble though the auto desktop resizing with this is not working.