Cannot dual-boot Windows 7 and Ubuntu?

I had Ubuntu 11.10 on my laptop, then I determined to install Windows 7 and keep both of them on my machine (dual boot), then I installed Window 7.

And then Windows 7 was running, but Ubuntu didn't appear in the grub menu.

I then ran Ubuntu from a live usb disk and edited GRUB to make Ubuntu boot:

sudo mount /dev/DEVICENAME_FROM_STEP_ONE /mnt
sudo rm -rf /boot
sudo ln -s /mnt/boot /boot

Now Ubuntu 11.10 is booting automatically when the laptop start, but Windows 7 doesn't appear at all in the grub (there is no grub menu at all).

Now I want to let Windows 7 appear in the grub menu to let me choose (Ubuntu + Windows 7). I've read these commands but it doesn't work with me:

sudo gedit /boot/grub/menu.lst

• A large text file will open and at the bottom leave a line and add this:

• (Just a blank text file opened with me -not a large one- i don't know why)

  title windows 7 beta (Loader)
  root (hd0,1)
  savedefault
  makeactive
  chainloader +1
  

Do not type this line but if that does not work on re-boot try hd0,0 or hd0,2 and so on until it works.