Help-How do I get rid of QTTask.exe

Please help. A program called quicktime keeps getting in my computer. I don't know how. It shows up in my startup files as QTTask.exe, and it's in my add/remove programs as Quicktime. I never downloaded it, I don't use it and I can't get rid of it. I always uncheck it in my startup file and it always comes back when I reboot. I have also tried uninstalling it from add/remove programs and also from the link it has in my program file. But it always comes back!!! What do I do? Thanks!
-Kristy

Quicktime is relatively harmless, and in a lot of cases, it is needed to view .mov files from the web (a lot of online movie trailers require quicktime). However, I have never found a need for qttask.exe. Even if you remove qttask from your startup, it reappears. This is what I do: go to C:\Program Files\Quicktime and rename qttask.exe to qttask.exe.OLD (or whatever). That should get rid of it in your taskbar.

Sorry, but I do not know much about computers. How exactly do I rename that file? Do I have to go into MSDOS or something? Thanks!