How to download Virtualbox GuestAddition iso

First go to the Url "https://www.virtualbox.org". Then click on the link "Downloads" in the side menu.

In the appeared page click on the link named "VirtualBox 5.0.16 for Linux hosts".

Scroll down the appeared page. You will see a Url as shown in the picture below. Copy the same and paste in address bar

Now you will see a page as shown below. Click on the desired version.

You will be able to see the "VboxGuestAdditions_x.x.xx.iso" file. Click on it and the download will start

Downloading Mozilla Firefox Full Installer using Firefox

 

Go to the following url
    https://www.mozilla.org/en-US/firefox/new/

Click on the “Download a fresh copy” link under the button “Refresh Firefox”. It s highlighted in the below picture

It will take you to the download page and highlight the Firefox download link based on the currently installed language of Firefox

How to download Mozilla Firefox and Thunderbird with checksum

 

To download Mozilla Firefox with checksum go to the following url

http://releases.mozilla.org/pub/firefox/releases/

For Mozilla Thunderbird use the following url

http://releases.mozilla.org/pub/thunderbird/releases/