I somehow managed to get the Windows 7 option in GRUB when i installed opensuse 13.1 "bottle".
But that led to a big mess! I have mount the Windows partition to /home and i ain't able to run wine.....
now in grub the location of windows 7 is dev/sda1 therefore, i am not able to unmount the windows partition now

I want a way to chainload [multiboot] windows 7 through GRUB2 since it has a better GUI. I couldn't do that need ur help.

P.S: below is the error when i try to unmount windows partition [mount in etc/fstab by UUID]:

Failure occurred during the following action:
Unmounting /dev/sda1

Unmount failed.

System error code was: -3002

Continue despite the error?

Please help.