OK I did all this.
First of all I uninstalled limewire and immediately after that I de-installed Java.
Then I downloaded CCleaner and installed and ran that.
Right after that I ran Fix-it utilities' regcleaner which found some more invalid entries.

After this I did a file-find on everything contaning "Limewire". I founs a lot and deleted every file and dir concerning Limewire.

Did a reboot and CCleaner again. Just some minor entries removed, which was obvious.

Finally I re-installed Java JRE1.5 and Limewire, both in off-line setup. (I have them downloaded in my "installs" dir).

Limewire takes a lot of time to connect for a search but the downloads have already started. Meaning I can download but cannot search because there' is no connection????????
Limewire vanishes ahter about 20min or so, exactly like before but later.

I do not think this is a pain and even if I were, it would be nice to solve this prob. and the only way to do that is keeping up the spirit and go on!

I'm happy to be able to talk to you about this because there is a lot to learn from this even if you're a newbie (which to a certain amount I am).
Thanks for that!

BTW. I forgot to mention earlier:
The port on which Limewire "listens" changes with each new install. Right now it's on 4151 but it has been on 4636 or so and even on 1028 etc. Wierd.
And another thing is that after the crashes Limewire often started up with the "finish installation" series, where you could have your drive scanned etc.
Also the installed language is "Dutch". Which I never choose to use even though I am Dutch. All sorts of "crazy"
appearances.