Unwanted Pop-Up Messages

I recently purchased a laptop with Win XP installed. I
never configured Messenger, but set up all my email
accounts with no problems. Over the past few days I've
begun receiving many spam messages, some of them quite
vulgar. I tried to delete the .exe files in the Messenger
directory, but that didn't work. I've also tried
uninstalling using your run command "RunDll32
advpack.dll ...", but no success. My kids use this
computer, and this has really got to stop! Any ideas
would be most appreciated.

Fran Emerson