Installing Toucan

Hi there everyone,
This is my first post and I am a lay person, i.e. I don't know the jargon, but I hope I can make myself understood.
I installed Toucan on my external hard drive a while ago and I saw a new version and decided to update. However, I couldn't find the uninstall routine, so I went to Sourceforge support - there wasn't a Toucan specialist around - and described the problem. Support advised, if the routine wasn't there just delete the old version and install the new one. This I did.
Now I find I can't install the new or any version. I have tried to, several times but I just get the following message (which I have translated into English): "This programme can’t be started because the configuration is incorrect. To correct the problem reinstall the programme."
But, as I have said before, the programme doesn't work. It doesn't even open.
Does anyone have a suggestion as to what might have gone wrong? What I did was to put Toucan in MS Search and just deleted all the entries it found. Why that should affect the new installation I really don't know. Any ideas as to how I can get the programme working?