I've looked on my laptop which has access to the account and the saved password is not the correct one.

May be I'm missing something obvious, but if the password isn't the correct one, how do you expect it to work?

Because Thunderbird is telling me the saved password? If it's the saved password surly it's correct, if it's not I'm unsure how to go about finding the password..

I cannot follow your logic. Please explain in more detail what password on which computer you're talking about, which one works, and which one doesn't.

In any case, if the correct password got lost, talk to your IT folks to reset it on the server for that account.

Ok I'll try and explain it easier. I go to Tools > Options > Security > Passwords > Saved passwords which then brings up all the "saved passwords" for all of our email addresses. Im trying to set up our Sales@ email address with another computer, So i'm using the password that Mozilla Thunderbird has saved and it says it's incorrect, I don't understand how It can be wrong if it's saying it's the saved password..

And seeing as Thunderbird doesn't have dedicated support it's making it rather difficult to do anything..

I go to Tools > Options > Security > Passwords > Saved passwords which then brings up all the "saved passwords" for all of our email addresses.

I suppose this is on another computer, not the one you're trying to set up? If so, why is it so hard to be precise?

i'm using the password that Mozilla Thunderbird has saved and it says it's incorrect,

I'll have to guess again. Is this on the other computer, not the one you're trying to set up? If so, what does 'it says it's incorrect' mean? Are you trying to retrieve mail, and you do get an error?

I don't understand how It can be wrong if it's saying it's the saved password.

Not knowing how access to that particular account is organized, but it sounds like multiple people can access that account. So it's quite possible someone changed the password on the server while you still have an old one that you told Thunderbird to remember.

Im trying to set up our Sales@ email address with another computer,

If the above assumptions are correct, the problem is already on the other computer. So I'm not sure how this is relevant.

And seeing as Thunderbird doesn't have dedicated support it's making it rather difficult to do anything.

Thunderbird is a community project, and that doesn't have the resources for paid support stuff. This forum is the official Thunderbird support venue. If you want 'dedicated support' you can hire a consultant to fix your problems, or pay for a commercial product which includes support.

For the time being it would certainly help if you could describe your problem precisely when being asked questions. Don't assume the people trying to help have a crystal ball and can see what exactly you're doing.

I'm not sure how I can explain it easier, This is what I had done when trying to set it up:

I put Thunderbird onto a pen drive (copied the files from the laptop), put it onto the new computer and ran Thunderbird, copied the settings off my laptop from Tools > account settings (All the Server settings for our sales email so Server name, user name, port, security settings) and put them on the new computer.

Once I had done that it shows me the email address in the panel too the left, but has a padlock symbol next too it, asking me to enter the password. I typed it the saved password on my laptop (Which you've pointed out has probably been changed now) after I've typed the password in a little box opens saying "login to sales@...... failed" and gives me three options, "Retry" "Enter New Password" and "Cancel"

So, I need to somehow change the password to something I know, which I can enter onto the new computer I assume, but I am unsure of how to do this. We don't have a trained IT guy where we work so we're having to just try ourselves!

Hopefully this explains it a little better for you.

I put Thunderbird onto a pen drive (copied the files from the laptop),

What does that mean? What exactly did you copy to the pen drive? The Thunderbird installer? The profile? I'd expect the Thunderbird profile, but you didn't mention that. What's so hard with providing exact information?

put it onto the new computer and ran Thunderbird,

To where? If this was the profile from the old computer you'd be done here. But it sounds like you copied something else.

copied the settings off my laptop from Tools > account settings (All the Server settings for our sales email so Server name, user name, port, security settings) and put them on the new computer.

So are you saying you created the account on the new computer and set it up as your computer? It's still not clear to me whether you can retrieve mail for the account in question from your computer.

Once I had done that it shows me the email address in the panel too the left, but has a padlock symbol next too it

The padlock indicates a secure connection to the server. Since you mentioned that, don't you have the padlock for the account on your computer? If you took over the settings from your own computer, there shouldn't be any difference, right?

So, I need to somehow change the password to something I know, which I can enter onto the new computer I assume, but I am unsure of how to do this.

You'd need to do that on the server. Not knowing your environment there is nothing I can suggest. Are you running your own server? Is your server hosted by a provider? Are you using something like Gmail as email provider? I guess this isn't the first time an email password has been changed?