Hhhmmm... did you look at your startup to see if it's automatically installing itself? If you don't know how to check:
- Click Start, then click Run
- Type in 'msconfig' (without quotes)
- In the new window, click the Startup tab
- Check the programs that are starting up, and if any look suspicious, uncheck them, then click OK.
I would suggest uninstalling it first though, then running msconfig.
If that doesn't work, then... well, I dunno