Freeserve software much like AOL software can be very difficult to get rid of (I also seem to remember hearing that Tiscalli can be a problem too).
I had a problem geting rid of Freeserve, ie despite uninstalling it it kept making itself the default ISP. It burrows deep into windoze and seems to refuse to go away.
I cheated and formatted the hard drive to get rid of it. If editing the registry is the solution (and I don't know if it is or isn't), you can get a free registry editor/cleaner through this site.
http://www.vtoy.fi/jv16/shtml/regcleaner.shtml
Unless it has changed, I found it to be easy to use with either a helpfull tutorial or help section. Anyway my puter has remained unscathed since installing it. Good Luck
For what it's worth, always try to find and ISP that allows you to manualy set up your connection. It's easy to do and more importantly easier to get rid of.