remove usb external drive with 11.04 installed

[squareyes]

Hi,
I am dual booting 10.04 with  an external drive (internal drive in a 
caddy mains powered) with 11.04 installed.
I have acquired a Western digital drive (usb powered) that I am trying 
to replace the mains powered drive, so unplugged
it, and installed 11.04 on the usb powered drive. Now nothing will boot 
unless I re-plug in the mains powered drive.
Menu on boot shows list of available to boot, but with old external 
drive unplugged, gives message can't find etc.

ubuntu 10.04 edit grub menu.1st  in Google only gives info on Grub2, (no 
menu.1st file)

My menu.1st file has no notation for either of the external drives (below)
All installed 10.04 kernels only showing, df in terminal shows  drives 
as sda1  sdc1  and sdb1 (listed in that order)


title        Ubuntu 10.04.3 LTS, kernel 2.6.32-33-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-33-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-33-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-33-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-33-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-33-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-32-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-32-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-32-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-32-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-32-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-32-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-28-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-28-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-28-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-28-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-28-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-28-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-27-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-27-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-27-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-27-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-27-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-27-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-25-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-25-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-25-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-25-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-25-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-25-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.32-23-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-23-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.32-23-generic
quiet
both
title        Ubuntu 10.04.3 LTS, kernel 2.6.32-23-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.32-23-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.32-23-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.31-22-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.31-22-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.31-22-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.31-22-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.31-22-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.31-22-generic

title        Ubuntu 10.04.3 LTS, kernel 2.6.28-15-generic
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.28-15-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro quiet splash
initrd        /boot/initrd.img-2.6.28-15-generic
quiet

title        Ubuntu 10.04.3 LTS, kernel 2.6.28-15-generic (recovery mode)
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/vmlinuz-2.6.28-15-generic 
root=UUID=eb827970-b141-42c5-a049-5885c15a439b ro  single
initrd        /boot/initrd.img-2.6.28-15-generic

title        Ubuntu 10.04.3 LTS, memtest86+
uuid        eb827970-b141-42c5-a049-5885c15a439b
kernel        /boot/memtest86+.bin
quiet

Could someone help me in how I can remove Grub menu entries for the 
external drives, and I will re-install 11.04 on the
usb powered drive.
Many thanks in advance.
Take care
Winton