Can't write to hard drive or change permissions

[alanrlow]

I have a laptop with xp on it, I wanted to try Ubuntu so I installed it on an 80gig external USB drive as there wasn't enough space on the lappys drive. I have been booting it and using Ubuntu for several weeks now and don't want to go back to windoze. So I bought a 160gb laptop drive, installed it in the lappy and used Clonezilla to clone the 80gb external drive to the new 160gb internal drive. Everything went well and booted up just fine except when I try to access the external drive or the other partitions on the internal drive I am told I don't own the drive and don't have permission. I had full permission to read and write everything before, what's changed and more importantly, how do I get it back?
I am using Ultimate Edition (Ubuntu Jaunty Jackalope based) Gnome Version: 2.26.1
If it helps
alan@alan-laptop:~$ mount
/dev/sda1 on / type ext3 (rw,relatime,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
lrm on /lib/modules/2.6.28-15-generic/volatile type tmpfs (rw,mode=755)
securityfs on /sys/kernel/security type securityfs (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
/dev/sdb3 on /media/disk type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096)
/dev/sda2 on /media/Backup type ext3 (rw,nosuid,nodev,uhelper=hal)
gvfs-fuse-daemon on /home/alan/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=alan)
alan@alan-laptop:~$ sudo fdisk -l

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x4c61c665

Device Boot Start End Blocks Id System
/dev/sda1 * 1 6016 48323488+ 83 Linux
/dev/sda2 6654 19457 102848130 83 Linux
/dev/sda3 6017 6653 5116702+ 82 Linux swap / Solaris

Partition table entries are not in disk order

Disk /dev/sdb: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x4c61c665

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 6016 48323488+ 83 Linux
/dev/sdb2 9217 9729 4120672+ 5 Extended
/dev/sdb3 6017 9216 25704000 7 HPFS/NTFS
/dev/sdb5 9218 9729 4112640 82 Linux swap / Solaris

alan@alan-laptop:~$ ls /dev/disk/by-uuid -alh
total 0
drwxr-xr-x 2 root root 140 2009-09-17 19:08 .
drwxr-xr-x 6 root root 120 2009-09-18 03:02 ..
lrwxrwxrwx 1 root root 10 2009-09-17 19:08 380f1dd1-27be-44db-ae8a-7f7e25f616fb -> ../../sdb5
lrwxrwxrwx 1 root root 10 2009-09-17 19:08 595cedab-c26a-4a20-9e21-233403e431b9 -> ../../sdb1
lrwxrwxrwx 1 root root 10 2009-09-17 19:06 6EB677C007AE6056 -> ../../sdb3
lrwxrwxrwx 1 root root 10 2009-09-18 03:02 90906763-efa3-4eab-a675-5a4c3e91a5f7 -> ../../sda2
lrwxrwxrwx 1 root root 10 2009-09-17 19:08 ff79f51d-e7b8-4548-be51-221c67147ca7 -> ../../sda3

This is my fstab

# /etc/fstab: static file system information.
#
# Use 'vol_id --uuid' 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 defaults 0 0
# / was on /dev/sdb1 during installation
UUID=595cedab-c26a-4a20-9e21-233403e431b9 / ext3 relatime,errors=remount-ro 0 1
# swap was on /dev/sdb5 during installation
UUID=380f1dd1-27be-44db-ae8a-7f7e25f616fb none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0

Anyone know what has gone wrong? Please be gentle as I'm nubie.
Thanks,
Alan.

[whych]

In all linux/unix systems, access rights to devices are set according to the permissions that are set for the logged in user.
By default, all users are able to list/read the contents of a directory, but do not have the right to change files or write to the directory.
The only user that has permission to read, write and change contents is root or the superuser (su).
To be able to wite or modify the contents of the usb drive, you need to log in as root and change the permissions to allow yourself read/write access.
Have a look at tutorial 5 in this link: UNIX / Linux Tutorial for Beginners

This is a general tutorial for all *nix systems and will give you an idea of linux.
For distro specific help, search the forum and you will probably find someone has asked the question before.