start - run - msconfig - qttask (uncheck it)
“start - run - msconfig - qttask (uncheck it)”
That will leave windows messages saying that you are using a system config... etc.
Easiest thing by far is to use the Quicktime uninstaller or Windows ad/remove programs tool.
Worse comes to worse, search for the quicktime directory and delete that. Restart. Then use a registry cleaner (like Wise Registry Cleaner— Download.com).
It should be gone.