Have you uninstalled the corrupted version of Limewire? If so and you still have the problem you could try System Restore, if the problem still continues post a messge and I can email you a claen non-corrupt Lime installation - download it at work and take home.
I've never had any problems with it - it seems a strange concept that any company would put a free product out that would alienate people and prevent them from purchasing the full version. I can't belive any company that operated in this would continue.
Do you want a clean and complete version of Limewire emailed to you?
No clear on this, but are you saying that you haven't had an Av on your machine (and presumably only the Windows firewall)?