RXCLUS is currently not specified to work under Windows Vista but you can use it anyway with a simple trick.
The
problem is that this software requires write access to its directory
(usually C:\Program Files\RXCLUS), which is granted by Windows Vista
only if you are using an account having administrator privileges, else
the software will get a read only access and refuse to start.
Solution 1
Install RXCLUS at another place then "C:\Program Files", for example: C:\RXCLUS.
Solution 2
Install RXCLUS in "C:\Program Files" and use the option to run RXCLUS as administrator. Here is how to do that:
first install RXCLUS in its default folder (C:\Program Files\RXCLUS);
right click on the RXCLUS shortcut which was created by the installer;
in the shortcut tab, click on the "Advanced..." button;