If you want to completely get rid of Spybot-S&D 1.4 (also earlier versions) and the Add/Remove doesn't help, you can delete the installation folder (usually C:\Program Files\Spybot - Search & Destroy\), then download this very small fix and execute it (important! - this will remove all remains from the registry) (this also applies to earlier versions).
If you just want to upgrade to a newer version, please follow the same instructions like above and then install the new version.
After following these instructions please restart your system so that the changes can take place.
Also, neither the automated uninstall nor the manual uninstall like described above will remove the following directories, which you will have to remove by hand:
* Windows 95 or 98: C:\Windows\Aplication Data\Spybot - Search & Destroy\
* Windows ME: C:\Windows\All Users\Application Data\Spybot - Search & Destroy\
* Windows NT, 2000 or XP: C:\Documents and Settings\All Users\Application Data\Spybot - Search & Destroy\