I have installed and uninstalled Limewire 8 times now, over the last three days, on my Vista pc. I have run spyware and antivirus everytime, and have everytime come back with a clean bill of health. So it can only be a Limewire software problem.
The other thing to watchout for is if you click on start, then search and type in for instance wi as i have done there should pop up a load of small ZIP or RAR files all at 622 kb and all downloaded at the same time. My last clean up of these files took two whole evenings as they are located in a hidden file named simply '. If the cleanup goes wrong it can lead to a major headache as if it says that it cant be deleted as the "file location doesn't exist try again" you have to delete file ' by opening file location, and then click on the zip or rar file to delete it then click yes to create the file locaton and then re-click delete to delete the zip file then re delete the file location. And so on and so forth for every junk file that has downloaded, in my case 2300 of them.

Hope this helps as all of my friends have had this problem with limewire on Vista machines and as yet have not been able to fix it.