In order to install List Fields you need to have so-called administrators rights in order to do so. If you haven't got such rights, you will see this screen:
When you log on to a computer, your user name and password grant you access to the computer. In modern operating systems like Windows 2000 and XP it is possible to control what a user can- and can't do. This is done through so-called access rights. You have different levels of access rights, and at the top - with god-like powers, throne the Administrator. Anybody with so-called administrators rights can do anything on the computer. Other levels, such as the User-level, can't do nearly as much on the computer, other that just use it and the installed programs.
In order to install List Fields you need to create directories, access and write to the registry and write files in restricted areas etc. To do all this, you need administrators rights. Later, in order to use List Fields, you only need Users rights.
If you see the screen above, then the installer has determined that your current user name hasn't got sufficient access rights. You can do one of these options:
In Windows 95, 98 or ME you always have Administrator rights, and can do anything - also installing applications.