This is from Kanotix installer, which is now Knoppix installer too:

http://forum.kanotix.net/viewtopic.php?t=180

13. Next you will be asked "Choose where the boot loader (grub) shall be installed. Select "mbr: master boot record", and select "Next". If you use a different bootloader and wish to continue to use a different bootloader then of course installing grub to mbr is a bad idea, the best option here is to install it to partition IF this is the case.

I don't say this is best solution, but this is easiest for beginners...