The 1st thing I'd recommend is to get either AdAware or Spybot... they will
search your system for adware and/or spyware and can clean it off (I use
AdAware more mself).
Then run an antivirus program to see if there are any viruses on your
system. I use AVG Antivirus (www.grisoft.com)
If you are using XP/XPPro, you need to turn off Messenger Service (not MSN
Messenger or Windows Messenger). See this link: (read instruction at top of
page)