Actually the question says it all, but let me tell you what I did, so u may find exactly what might have went wrong:

I have Win 8 installed on 500 GB HDD.

SO I shrunk it four times for:

partition 1 - the original partition containing Win 8 sys (118GB)

partition 2 - NTFS formatted for my data (188GB)

partition 3 - NTFS formatted for my data (100GB)

partition 4 - NTFS formatted for Linux distro 1 (I reformatted it to ext4 during Ubuntu installation) (25GB)

partition 5 - NTFS formatted for Linux distro 1 (21GB)

So now I booted Ubuntu from USB (created from ubuntu-12.04-desktop-amd64.iso) and deleted last two partitions 4 and 5 to create:

partition 1 - ext4 where I installed Ubuntu (25GB)

partition 2 - Swap (4GB)

partition 3 - unallocated space, not formatted yet (17GB)

Ubuntu installation said it installed successfully and that I have to restart to boot in Ubuntu. But when I restart Windows 8 auto booted - there was no dual boot.

After that I devided above 100GB partition to 80Gb and 20GB ones (since I read online that I should have /home in separate partition for convenience, so I created 20GB partition for it)

So I went on to manually create boot entry using EasyBCD as below show in picture at below link

http://s19.postimage.org/dof2zuvw3/Free_BCD.png

When I created the entry, FreeBCD showed the information as follows:

Windows Boot Manager
--------------------
identifier              {9dea862c-5cdd-4e70-acc1-f32b344d4795}
device                  partition=\Device\HarddiskVolume2
description             Windows Boot Manager
locale                  en-US
inherit                 {7ea2e1ac-2e61-4728-aaa3-896d9d0a9f0e}
integrityservices       Enable
default                 {ea8167ad-d189-11e1-90e4-ab2f09569dcc}
resumeobject            {ea8167a3-d189-11e1-90e4-ab2f09569dcc}
displayorder            {ea8167ad-d189-11e1-90e4-ab2f09569dcc}
                        {ea8167b1-d189-11e1-90e4-ab2f09569dcc}
toolsdisplayorder       {b2721d73-1db4-4c62-bf78-c548a880142d}
timeout                 10
displaybootmenu         Yes

Windows Boot Loader
-------------------
identifier              {ea8167ad-d189-11e1-90e4-ab2f09569dcc}
device                  partition=C:
path                    \Windows\system32\winload.exe
description             Windows 8
locale                  en-US
osdevice                partition=C:
systemroot              \Windows
resumeobject            {9bc7fdf7-3ae0-11e2-be77-806e6f6e6963}

Real-mode Boot Sector
---------------------
identifier              {ea8167b1-d189-11e1-90e4-ab2f09569dcc}
device                  partition=C:
path                    \NST\AutoNeoGrub0.mbr
description             Ubuntu

Notice the last bolded entry created.

Howevever after thet, when I rebooted it firstly showed old DOS like bootloader (no Windows 8 UI based bootloader) with two entries Windows and Ubuntu.

Windows 8 was booting correctly but I was getting an error while booting Ubuntu taking me to GRUB Rescue.

Please help am new to Linux world.