Ah, uninstalling, a function of Application Packaging, which is wot I do.
IsUninst.exe is the uninstall program provided by Installshield, and installed by the Creative Labs software. The executeable part (isuninst.exe) is generic, and is usually accompanied by a file specific to the application which is usually (but not always) called "uninst.isu". You need to enter the required command line to run the uninstall.
The good news is that the command line is stored in the registry when the application is installed. To find the correct command line, open Regedit and search for isuninst.exe. You may find more than one entry, as lots of companies use Installshield, so look for the one which matches your application. You should find a registry value called UninstallString, with the data looking like this "C
WINNT\ISUNINST.EXE -f"C
Program Files\Common Files\Adobe\Acrobat 5.0\NT\Uninst.isu"" This is the command line you need to use, simply paste it into the Start - Run box and it will remove itsself.
It is possible to suppress the Add / Remove Programs entry, so it may be that Creative Labs wanted to make it hard to remove it. It is also possible to remove the uninstall support altogether, in which case your only option is to start deleting files, services, registry entries and so on - definitely not an approach I would recommend to anyone.
Hope this helps, let me know here or by email how you get on and if you need anything further.