how do I check Ubuntu 10.10 with MD5sum

https://help.ubuntu.com/community/HowToMD5SUM

When I type in terminal cd download_directory it said not found !

"cd download_directory" means go to folder where you have downloading file.
E.g. if you downloaded in your desktop, it's
  cd # to go in your home directory
  ls # to list all files and folder
  cd desktop

Sorry I new to this!

I have copied from my "Download Folder" Ubuntu 10.10.iso file to desktop and can see it there.

Then how do I RUN MD5SUM which I can see in the file on my desktop?

I have read

https://help.ubuntu.com/community/HowToMD5SUM

But I still do not understand...sorry

Can I Upgrade from Ubuntu 10.04 which I upgraded from 9.10 (I think is was) in April

If so how is this done?

Yes, if you run System->Administration->Update manager, you should have at top a button to upgrade from 10.04 to 10.10. If you have not, check in parameter if your update is restricted to LTS. In this case, remove this restriction.

If the file is on your desktop, type this in the terminal (Applications > Accessories > Terminal):
cd ~/Desktop
md5sum *.iso

Thanks to delance 2010-10-12 Yes I been able to Update to 10.10 as you said thank you

Thanks to Marc Stewart 2010-10-12 Although it did produce a checksum I was unable to match it up with either "Downloads of 10.10" I have on my Desktop

Can you Help please as I would like to have a CD as a backup as this computer crashes A LOT!

If the hash isn't what you were expecting, that suggests that either the download was corrupted or you're looking at the wrong hash. (I've misread hash lists before so I know how easy this can be.)
Which disc images did you download, and what MD5 hashes were produced for them?

As an alternative to the standard HTTP/FTP download, you might want to consider using the torrent. That method has in-built checks that the data has been downloaded correctly, and as a bonus you'd be helping other people download the disc image too.

Sorry, but I don't understand. What you need to backup is your data in /home/rich. You will always be able to download again 10.10 installation CD.
Can you clarify your need ?
If you need to backup your "home", run command
   du -sk $HOME
and post result.
If you need a CD to be able to boot computer and install again, download ISO image from Ubuntu and MD5 check the ISO file before burning it.

What I am trying to do is have a backup of an installation CD with Ubuntu 10.10 on it:-
So that I can install (or run from) from this CD on this or any other computer.

I have an external HD so I have no problem backing up any files.

The result du -sk $HOME was:-

richard@richard-desktop:~$ du -sk $HOME

21295884 /home/richard

richard@richard-desktop:~$

Still having problems with ISO image download:-

How do I use torrent to download an ISO image please.

Thanks to delance 2010-10-12 Yes I been able to Update to 10.10 as you said thank you and I am using it now....

http://www.ubuntu.com/desktop/get-ubuntu/alternative-download#bt

Well, I followed your link above.....and after 6/7 hours and 1.3Gbit uploaded

ubuntu-10.10-desktop-i386.iso

I cannot SEE any file ! Were is it, and by the way Transmission/Torrent is still uploading now.....!

How long does it take?

It depends of ratio between people who upload and ones who download.
You can also do a direct download in appropriate mirror:
     http://www.ubuntu.com/desktop/get-ubuntu/alternative-download#dvd

I will try later to save an .ISO copy

Thanks for your help