virtualbox.org

Hi,

I am trying to install guest additions in Linux Redhat 3, but i cannot get it done. It show me the error as the following:

"Please install the build and header file for your current linux kernel.
The current linux kernel version is 2.4.21-4.EL
Please install the GNU compiler.
Problems were found which would prevent the Guest Additions from installing.
Please correct these problems and try again"

Could you please advice to how to solve this problems??

Do what it is telling you to do. Install the build and header files before you try to install the guest additions.
Google using this guest additions in redhat 3 if you need help with the Linux commands.
Or look here: VirtualBox FAQ