Trying to read my Windows drive through Xubuntu

Hi, I will try to describe my problem as clear as possible, if someone could help I would appreciate very much!

My Windows XP computer crashed (whenever i try to boot windows, it crashes during boot process and restarts.
Now the problem is: There are a lot of documents on my C: drive which i want to take off the hard disk. So I thought it might be an idea to boot through a Xubuntu (8.04) CD.
So I inserted this CD, and chose "Try-out without installing".

Now I am logged in, and followed the instructions on this website:
http://technical-itch.co.uk/2006/11/06/how-to-access-your-windows-hard-drive-from-ubuntu/

But when i came to " sudo mount -t ntfs /dev/hda1 /mnt/windrive -o “umask=022″ " , i got this error:

$LogFile indicates unclean shutdown (0, 0)
Failed to mount ‘/dev/sda1′: Operation not supported
Mount is denied because NTFS is marked to be in use. Choose one action:

Choice 1: If you have Windows then disconnect the external devices by
clicking on the ‘Safely Remove Hardware’ icon in the Windows
taskbar then shutdown Windows cleanly.

Choice 2: If you don’t have Windows then you can use the ‘force’ option for
your own responsibility. For example type on the command line:

mount -t ntfs-3g /dev/sda1 /mnt/windrive -o force

Or add the option to the relevant row in the /etc/fstab file:

/dev/sda1 /mnt/windrive ntfs-3g force 0 0

Well, i tried the "mount -t ntfs-3g /dev/sda1 /mnt/windrive -o force" but it gives this error:

mount: only root can do that

Can someone please tell me how i should continue? I'm a complete Xubuntu newbie so if you could please keep it simple for as far as possible?:)

Greets,
Joost Mulders