You may have to run a registry cleaner.
Do a Google search for "Wise Registry Cleaner", download, install, and run it.
This is a free program and on my system does an excellent job of quickly cleaning up my registry.
Uninstalling a program may remove it from your system but will often leave some info in Windows Registry and that may be where your system tells you the trial version is still installed.
Hope this helps. Post your results here.