Ok another newbie question.
Why do i have so much trouble deleting an unwanted downloaded programme?
I seem to do it but it always seems difficult, and then I'm not completely sure that its gone?
The uninstallers would be in the same location at the application, if they've created a folder. Sometimes, the uninstallers are in the original DMG file you used to install an application.
The rule of thumb, usually, is that if you had to go through a formal installation process (apart from my dragging the application icon to the Applications folder), there will be a formal uninstallation process as well.
Otherwise, just use the AppCleaner app I mentioned above, click on the Applications tab, check the ones you want to delete, click Search and then Delete.