Don't you hate it when someone mucks with your settings?!?!
OK, so I'm assuming you are on Windows XP although I'm sure Vista's settings will be similar. After a reboot of the laptop go to Start, Settings, Control Panel. There should be a Mouse Settings Configuration in the list. Once you are in there you should have a tab with the Touchpad settings (where you can change sensitivity, speed etc) and you will also see a setting for "Taps". Usually they are radio or check boxes that say "Tap to Click", "Tap to DragLock" etc. Wordings will vary depending on brand of laptop but this is generally where you can make those settings.
HTH, and if still lost then let us know the brand of laptop and operating system you are running for more specific details.
