How to Remove First-Installed OS from Dual-Boot System

Does the system only have one drive or is there 2 in the system?
Thanks

The system has only one hard drive, one DVD drive and one CD drive. Thanks.

Julianlouio

Additional data:
Mint 11 and Ubuntu 12.04 are located at /dev/sda1 and /dev/sda2 respectively.

Julianloui

If you remove /dev/sda1 (mint) in Ubuntu, then run:

sudo grub-install --recheck /dev/sda

It will reinstall Grub to the MBR and set it up (in case Mint was managing the boot)

You can resize your Ubutu partition in liveCD to the new free space, or make a fresh Ext4 partition and use it for casual user data.

You may want to also run:

sudo blkid

and check the partitions have the right UUID compared to that in /etc/fstab in Ubuntu.

Andrew,
Here are my blkid, /etc/fstab and 'fdisk -l' outputs. Linux Mint11 definitely occupies /dev/sda1. Thanks.
Julianloui

/dev/sda1: UUID="b4c9baba-bb06-48ab-992a-673b3eb1032c" TYPE="ext4"
/dev/sda5: UUID="24239e68-00a6-4ca6-8cc1-c7f1f421e991" TYPE="ext2"
/dev/sda6: UUID="9508a7a7-7306-4f64-9f0f-077ea15f0124" TYPE="ext4"
/dev/sda7: UUID="8816c492-5934-4303-a241-bd3dd5be005d" TYPE="swap"
---------------------------------------------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
# / was on /dev/sda6 during installation
UUID=9508a7a7-7306-4f64-9f0f-077ea15f0124 / ext4 errors=remount-ro 0 1
# swap was on /dev/sda5 during installation
UUID=22cc3707-a892-448d-9c7d-13e69f11d00f none swap sw 0 0
----------------------------------------------------------------------------------------------------------------------------------
'sudo fdisk -l' shows following partitions.

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006733e

   Device Boot Start End Blocks Id System
/dev/sda1 2048 44923922 22460937+ 83 Linux
/dev/sda2 * 56643582 156301063 49828741 5 Extended
/dev/sda5 153176064 156301063 1562500 83 Linux
/dev/sda6 58580992 153176063 47297536 83 Linux
/dev/sda7 56643584 58578943 967680 82 Linux swap / Solaris

Partition table entries are not in disk order