Open uTorrent and from the menu bar go to Options \ Preferences and under the General section uncheck the box next to Start uTorrent on system startup, then click Ok to close out of Preferences.
In Windows 7 or Vista go to Start and enter msconfig into the Search box.
In XP you need to go to Start \ Run then type in msconfig.
In System Configuration click the Startup tab then uncheck uTorrent and click Ok.
Now you won’t have UTorrent starting up automatically every time you restart your Windows machine.