How to dual boot Ubuntu and WinXP using two hard drives?

I really want to use Ubuntu. When new version is out, I will request free CDs from Ubuntu Shipit and will receive the CDs after two weeks from the request date. But yesterday, after struggling to install new hard drive into my PC, then I was successfully install Ubuntu and make it dual boot with my Windows XP.

My Ubuntu specs
It is really difficult for me to set them to dual boot from two different hard drive. My old hard drive has Windows XP installed and the new hard drive which 320Gb size, installed with Ubuntu. I only allocate 20Gb for Ubuntu. The rest of the empty space is for files storage.

How to make them dual boot?

To make dual boot using two hard drives, you must plug out your Windows hard drive first and make Ubuntu hard drive as Master. Slip in the Ubuntu CD and run the installation from it.
Once the Ubuntu has succesfully installed on to your Ubuntu drive, boot into your Ubuntu. Login with your username and password, and open up Terminal (Applications > Accessories > Terminal). Enter this line by line into the Terminal.
Note: We use “sudo” because we want to do our job as administrator.

cd /boot/grub
sudo cp menu.lst menu.lst_backup
sudo gedit menu.lst

The first line changes our directory to /boot/grub/. The second line is to make a backup copy of menu.lst file. The last line is use to edit menu.lst file.
Next, copy the below code

title Microsoft Windows XP
root (hd1,0)
savedefault
makeactive
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1

and paste it above

###BEGIN AUTOMATIC KERNEL LIST###

But if you want to make Ubuntu as your default OS, you can paste the code at the end of the file. We need to copy the above code into our menu.lst file because Windows does not like to be Slave. So we use this trick to fool it.
Then, what we need to do is, we want to display the Grub Menu when we boot up our PC. To do this, find

hiddenmenu

and replace with

#hiddenmenu

This step is optional. The default Timeout is 3 but I changed it to 10. You can set any numbers you want.
Then, save menu.lst file. Now, shut down your PC and plug back your Windows hard drive. Make sure that you set Windows hard drive as Slave because we want Grub to take care of the boot process.
Boot your PC and you will see, Microsoft Windows XP at the top line in the list. Below the line you will Ubuntu kernel. Choose your selection to proceed the boot process.

Why using this method?

There are many ways to make dual boot using two hard drives. But for me, I choose this way because if I want to format Ubuntu or if Ubuntu corrupted, I still have Windows boot manager to take care the process. And if I want to format Windows, I still have Grub to take care the boot process. Other than that, by doing this way, we does not touch any of our Windows settings. So our Windows is safe.