This how-to is not designed for a re-installation of the same version. Ubuntu 14.04.x LTS is still supported until April, 2019. This old wisdom is valid for every operating system under the sun..... Let the DVD check itself for errors: in the beginning, hit the space bar and choose "Check disc for defects" in the DVD boot menu. When no errors are found, boot your computer from the DVD again and choose "Try Ubuntu". Establish internet connection and start the installation by clicking the desktop icon of the installer.
So if you're running 14.04 LTS now, it's wise to consider if you really want to upgrade at all, yet.... This is partly due to the configuration files that exist in the old version. During its course, the installer will use the unallocated space automatically, without notification, when you select the "alongside" option for the preservation of your existing Windows. So: after you've agreed to its proposal, the installer takes automatically care of the rest! Boot the old Ubuntu version for the last time and backup your documents (duh) and your Firefox bookmarks.
Every two years, a new LTS (long term supported) version of Ubuntu becomes available.
If you've already got Ubuntu 14.04 LTS Trusty Tahr on your computer and you want to upgrade to Ubuntu 16.04 LTS Xenial Xerus, this is probably the best way to do it. Ubuntu 14.04 is an LTS version and therefore of the highest quality, like 16.04 LTS. When a new Ubuntu version is made available, an upgrade button appears in Update Manager (for LTS versions this happens only when the first point edition of a new LTS version has become available). With a clean installation, with previous formatting of the target partition, you have the least chance of troubles afterwards.
The instructions below have been tested with Thunderbird 10 which is available in the Ubuntu 11.10 Oneiric Ocelot official repositories and Thunderbird 11 (will probably be available in the Ubuntu 11.10 repositories soon; is already available for Ubuntu 12.04).
Click "Next" and Thunderbird should start importing all your calendar events.
It happened to me once, and that was no joyful discovery. Click in the Ubuntu sidebar on the icon of your home folder. It should be reformatted, so make sure that the format box is ticked. Now finish your shiny new Ubuntu installation with some polishing (10 things to do).
This may take a while and the Thunderbird window may appear to freeze (but it's actually working in the background).
They sometimes cause complications in the new version. Note: the swap partition needs to be unmounted before you can destroy it. However, should you feel so inclined, you can also do a manual partitioning. I advise against creating a separate home partition. The easiest way to save your Firefox bookmarks is from within Firefox itself: Bookmark button - down below: Show All Bookmarks - change "Import and Backup" to "Export...." Copy the file to your USB memory stick. Then open file manager Nautilus with root authority: Click on the grey Ubuntu logo (Dash home). File manager (Nautilus) toolbar: View - tick "Show Hidden Files".Besides, a clean installation is usually a lot quicker than an upgrade. The "clean" upgrade method that's being offered by the installer on the DVD of the new Ubuntu, is dangerous. In Gparted, you can do that as follows: click with the mouse on the swap partition, then right-click with the mouse, and choose This website is being sponsored by Google Ads. Then you're also blocking my earnings from advertisements.... However, if you already have a separate home partition, and want to keep it, this is a safe and easy way to upgrade to a new Ubuntu. After you've installed the new Ubuntu, you can use the Import function in Firefox to, well, import your old bookmarks. Boot your computer from the new Ubuntu DVD and choose "Try Ubuntu without installing". Mount the home partition: click on the icon of your Home folder in the side panel. In all user accounts on the home partition, delete all hidden files and directories with configurations (all directories and files that start with a dot, such as .Do not use it, because that particular method is unreliable: it may erase not only the old Ubuntu but all other operating systems (Windows, other Linux distributions, ...) and data partitions on your hard drive as well. Then use this fine disk partitioner, to completely destroy the Ubuntu partitions. All actions you do in Gparted have to be confirmed by a click on the Apply button in the panel (the green tick V), before they are being executed. Note: don't format the Ubuntu partitions, just destroy them. If you wish to support my website, you can configure your ad blocker to make an exception for this website. If you want to save your e-mails, copy this directory to the USB memory stick. Reboot anew from the DVD and let it check itself for errors. When no errors are found, boot your computer from the new Ubuntu DVD and choose "Try Ubuntu without installing". Establish internet connection and start the installation by clicking the desktop icon of the installer. During installation, the best choice is now manual partitioning.This unreliable method might do this in spite of the fact that it promises to erase only the old Ubuntu.... Ubuntu itself will be placed on the root partition: give it the mount point "/" (without the quotation marks).
You can use Lightning to get a calendar that's fully integrated with Thunderbird, but what about Google Calendar synchronization?Well, there's an extension called "Provider for Google Calendar", which lets Lightning read and write events to Google Calendar.