Install dual system(Ubuntu 10.04 and Win7,Ubuntu install first)

Two Hard Disks. Ubuntu 10.04 Installed on disk one. Now I want to install Win7 on disk two....here's the step:
- Disconnect the power connection of disk one;
- Install Win7 on disk two(just like normal installation -one system,one disk)
- Connect the power connection of disk one
- Boot PC with Ubuntu 10.04 live CD;
- Reinstall GRUB2    
      a. check two disks' name
       $ls /media
             linux  win7
       b. reinstall GRUB2 on two disks
       $sudo grub-setup -d /media/linux/boot/grub /dev/sda
       $sudo grub-setup -d /media/linux/boot/grub /dev/sdb
- Reboot PC, you will see startup menu there