Just install it. Ubuntu should pick up on the fact that Windows is installed and configure GRUB appropriately. You just need to be sure to remove GRUB if you ever decide you no longer want to have Ubuntu installed.
Hi I have Windows 7 Ultimate (64-bit) installed on one drive, and my other drive is blank. What would be the best way to install Ubuntu 10 on the blank drive so as to not mess up the boot loader? Thanks.