If you have uninstalled it via the Control Panel, well, then that wasn't a good idea. Always use the unistall.exe of LW.
What I would do is, first open the Windows Task Manager (press crlt & alt and once on "delete" to open it), then go to the Process tab and look whether there is a limewire.exe process running. If so, force it to end.
Then use the Search function of your computer to find all files remaining from LW by using the search query "limewire". All files that you have found you should delete.
Then go to "START">"Run" and type " regedit ". The registration will open and there you go to "Local Machine">Software and delete the folder called " LimeWire".
That should it be......
If you have, however, uninstalled LW using the uninstall.exe, then my best bet would be that you caught yourself a virus.......
Check your system using any of these programs (I reckon using all of them):
http://www.lavasoftusa.com/software/adaware/(free) http://www.grisoft.com(good free AVG) http://www.ewido.com(>>now called AVG Anti Spyware<< free 30 day trial -the best in my opinion) http://www.ccleaner.com/download/(free) Spybot - Search & Destroy (FREE)
If you can't get rid of it go here and get some free computer help:
http://norbiesworld.co.uk/computerhelp 