Well, that is not recommended, as you may regret it soon, but, that's your right :-)
In fact you just need to uninstall the boot loader (generally GRUB) from the Master Boot Record (MBR). To do so, boot under DOS and run the command
fdisk /mbr |
If you have another OS, consult its doc about doing the same thing.
Goodbye, and Thanks for using Linux-Mandrake hope to see you again soon :-)