thanks for your inputs!!! I understood what i was doing wrong and by the time i read new replies here to my thread, it was confirmed. I shouldn't have done grub things thro' a live usb.
Here's what i did.
I cleaned my mistakes by gparted.
I installed Ub 12.04 normaly.
after installation when i did boot from newly installed Ub i followed the video: https://www.youtube.com/watch?v=WawYFfTtqPc
and installed grub2 in my grub2 dedicated partition which is /dev/sda1 of 500mb
then as we know i have installed only precise pangolin so i don't have a second distro to test my grub2 dedicated partition setup.
so i had read this thread: http://linuxforums.org.uk/index.php?topic=10264.0
so i decided to go for Simplicity 14.07 final just for a change.
i made a change in my partition table:
madmandy@Thinkpad-x121e:~$ sudo fdisk -l
Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x0000f32c
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 17803263 8388608 82 Linux swap / Solaris
/dev/sda3 17803264 101689343 41943040 83 Linux
/dev/sda4 101691390 625141759 261725185 5 Extended
Partition 4 does not start on physical sector boundary.
/dev/sda5 101691392 185577471 41943040 83 Linux
/dev/sda6 185579520 206551039 10485760 83 Linux
/dev/sda7 269467648 625141759 177837056 7 HPFS/NTFS/exFAT
/dev/sda8 206553088 269465599 31456256 83 Linux
Partition table entries are not in disk order
and installed it on /dev/sda6 however, install procedure was not cool! shame on you simplicity! You do not make justice to your name as per install procedure. However, i can see why it is so. Being the os so light weight it may have many constraints on development, thus the complications!
Further, now i know on reboot i will not have grub menu now itself while i have a self setup grub which i need to update myself.
so i did boot in Ub 12.04 and followed grub-mkconfig part of the video again and there it was the unknown linux distribution in my grub menu. however, i had to change some timeout value to see the grub menu.
Now coming back to questions, i have two of them this time and i request you guys to play along and answer me in organised manner as i ask them in an organised manner.
Q1: while installing Simplicity it (i m not sure) detected my grub somehow and showed me a text file in which was written add following content to your menu.lst file in /boot/grub if you have grub already installed otherwise click in dialogue box to finish installation and run grub install seperately to install grub to your mbr......
What is menu.lst and why don't i have it?
Q2:see snap and what is that the dialogue box wants to tell me?