Today, I noticed that every 2 minutes or so, Limewire automatically opened and connected. I scanned my computer and rid it of anything that could be the work of a hacker, and then un-installed limewire. Now a window with a code still pops up every once in a while saying that I can not open limewire unless I install it.

Any idea what this is or how it can be stopped?

Btw I am running on Windows XP...

Most likely a virus from gnutella network. Don't download files less than 2,000 KB (2 MB).
See the blue link at bottom of this page -> http://www.gnutellaforums.com/genera...wers-here.html

Your computer's probably infected. This thread has a few fixes to try...if nothing helps you'll find links to help sites that offer specialised support for malware problems.
http://www.gnutellaforums.com/open-d...sible-fix.html

Before you uninstalled LW, did you also have the problem of not being able to access LW's options? If so, download AVG Free AV. Update AVG & scan your computer. You could even try scanning with AVG anyway, even if you didn't have a problem with options...if might help with the worm that's causing the popping up problem
http://www.gnutellaforums.com/downlo...s-options.html

Also read WARNING: Viruses on network you should be aware of!
Always make sure that you're using a good AV program. Keep it updated & use it to scan all files that you've downloaded, before you open them.