With 7 you should be able to turn off auto-updating since I can do it on 8.1 64 bit. Go to Control Panel\System and Security\System or maybe just search for "Windows Update". Don't know since I don't have a 7 system to look for it. But anyway you'll get to the Windows Update and see settings. You want to make sure to choose the "red X" setting that says "Never check for updates (not recommended)".
Actually, IIRC, in 7, there's an "action center" in the icon tray in your taskbar. There should be a Windows Update button there somewhere. Choose the setting with the red X.