In order, go to msconfig and see if it has a boot there in startup. Then, go to services.msc and find the service it's using, it should be set to automatic. Right click > stop the service, then right click > properties, and find the dropdown menu to disable it. Then go to control panel > remove programs and find your software, and remove it.
If anything's different for you (or I worded something wrong), this is the basis of what I do when I have to get rid of stupid shit. Works 99% of the time (the other 1% being a hardcore virus). So figure out what I mean.