Upgrade von Ubuntu
Network upgrade for Ubuntu desktops (Recommended)
You can easily upgrade over the network with the following procedure.   
-  Start System/Administration/Update Manager.   
-  Click the Check button to check for new updates.   
-  If there are any updates to install, use the Install Updates button to install them, and press Check again after that is complete.  
-  A message will appear informing you of the availability of the new release. 
-  Click Upgrade.   
-  Follow the on-screen instructions. 
 
Network upgrade for Ubuntu servers (Recommended)
-  Install update-manager-core if it is not already installed: sudo apt-get install update-manager-core  
-  edit /etc/update-manager/release-upgrades and set Prompt=normal  
-  Launch the upgrade tool:   sudo do-release-upgrade 
-  Follow the on-screen instructions.    
 
Upgrade from 8.04 LTS to 10.04 LTS
Network upgrade for Ubuntu desktops (Recommended)
You can easily upgrade over the network with the following procedure.   
-  Press Alt-F2 and type update-manager –devel-release   
-  Click the Check button to check for new updates.   
-  If there are any updates to install, use the Install Updates button to install them, and press Check again after that is complete.   
-  A message will appear informing you of the availability of the new release.  
-  Click Upgrade.  
-  Follow the on-screen instructions.    
 
Network upgrade for Ubuntu servers (Recommended)
-  Install update-manager-core if it is not already installed: sudo apt-get install update-manager-core 
-  edit /etc/update-manager/release-upgrades and set Prompt=lts  
-  Launch the upgrade tool: sudo do-release-upgrade –devel-release 
-  Follow the on-screen instructions. 
Other upgrade options exist, please view the Upgrade Notes to learn more.