How to Install kernel interface?

Hello!

I try to install a new driver for my graphicscard into my Linux Mandrake 10.1. But when I run the driver installer i get a message:

No precompiled kernel interface was found to match your kernel. would you like the installer to attempt to download a kernal interface for your kernel from the NVIDIA ftp site....

If I click Yes, the installer fails to download any kernel interface.

If I select No I get:
No precompiled kernal was found ...; this means that the installer will need to try to compile a new kernal Interface.

Then I get:

ERROR Unable to find kernal source tree for the currently running kernal. Please make sure you have installed the kernel source files for your kernel; on Red Hat Linux systems, for example, be sure you have the "kernel-source" rpm installed. If you know the correct kernel source files are installed, you may specify the kernel source path with the '--kernel-source-path' comand line option.

This last message is above my knowledge. So if any one could explain to me what to do, in an easy step by step way, to get this right it would be great.

Best regards
Fredrik