Now that made it work
to start fdisk on internal memory you should type
And yeah updated the step by step process

And btw don't forget to post here the updated df -h so I could see how your partition table look.

pphheewww thxxx alot I feel relieved seeing fdisk work!!

ohk I did as you directed..but I feel the last step where I have to enter btw 1-4 I enter w..is that correct..heres what I did:

~ $ root


BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso30+0m5) built-in shell (ash)
Enter 'help' for a list of built-in commands.

Nokia-N900:~# fdisk /dev/mmcblk0

The number of cylinders for this disk is set to 977024.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): d
Partition number (1-5): 4

Command (m for help): d
Partition number (1-4): 1

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-977024, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-884865, default 884865):
Using default value 884865

Command (m for help): t
Partition number (1-4): 0c
Value out of range.
Partition number (1-4): w
Partition number (1-4):
(I rebooted..but no difference..the memory is still 50/50 divided) :s

and this is the df -h result:

~ $ root


BusyBox v1.10.2 (Debian 3:1.10.2.legal-1osso30+0m5) built-in shell (ash)
Enter 'help' for a list of built-in commands.

Nokia-N900:~# df -h
Filesystem Size Used Available Use% Mounted on
rootfs 227.9M 127.5M 96.2M 57% /
ubi0:rootfs 227.9M 127.5M 96.2M 57% /
tmpfs 1.0M 76.0k 948.0k 7% /tmp
tmpfs 256.0k 88.0k 168.0k 34% /var/run
none 10.0M 80.0k 9.9M 1% /dev
tmpfs 64.0M 4.0k 64.0M 0% /dev/shm
/dev/mmcblk0p1 18.7G 710.9M 17.1G 4% /home
/home/opt 18.7G 710.9M 17.1G 4% /opt
Nokia-N900:~#

no difference ryt? :/

Opps sorry again I was wrong here
Wait a sec gonna update the steps 1 last time

The partition 1 which you are trying so desperately to delete does contain your /home!!! Do not do this!

Edit: I tried to send you a p.m. with a small howto, but it turned out it will be an email.

Edit!
Michaa is right partition1 contains home you should move that first

Im a noob at this
All I want to do is to return the emmc as it was by stock

You need to do this first(Not very sure thou)
Then proceed with this updated steps
Updated steps
God! This is going risky lol! I thought you just repartitioned MyDocs
Good thing it failed and I let you show df -h

so I should do this before/after which step??
whats the possible risk here?

is'nt My partition table clear..should I post it again??

Here try this...
Halt and check if there's some error output first. If no errors continue else post it here