If you have an older computer and your Ubuntu installation is running slow here is a list of things you can do to gain some speed:

• Go to System\Preferences\Session and disable all startup programs, this should free up a bit of memory by not loading them when you log in.
• Go to System\Preferences\Appearance and disable Visual Effects
• Go to System\Administration\Services and disable the ones you are sure you don't need. Do not disable services if you are unsure about what they do, eventually ask somebody if you don't know for sure if you need them. Some examples of services that can be safely disabled are: "Bluethoot ...", "CPU Frequency manager", "Folder sharing service", "Power management", "Printing ..."