IBM, now Lenovo, laptops come with an additional piece of software that allows you to control aspects of the ThinkPad laptop interface. This software overrides the settings in Microsoft Windows and can be used to administer and disable the laptop's pointing devices. Often times, the cursor will be unable to move because this software has disabled it. Additionally, you can turn the pointing devices on and off either through other software or hardware triggers.
Hotkeys
Press the "FN" and "F8" keys simultaneously to trigger the laptop's pointing devices on or off. This is the most common reason your pointing devices become disabled, through accidentally pressing the wrong function key. If this doesn't work to turn the touch pad back on, the mouse may be physically disabled by the ThinkPad software, ThinkVantage.
ThinkVantage
Press the blue "ThinkVantage" button to access the ThinkVantage software on any ThinkPad laptop. Attach a secondary pointing device to give yourself control of the pointer, and then click the "Synaptic TouchPad" or "ThinkPad TrackPoint" images to enable the devices. A green dot appears next to the devices when they're enabled. If this doesn't enable the laptop's pointing devices, the hardware itself may have been disabled by Microsoft Windows.
Device Manager
Open the Device Manager in the Microsoft Windows Control Panel. The Device Manager will let you scroll through all of your system's hardware devices and make changes to them, modifying or installing new drivers and configurations. Scroll down until you see the devices labeled "Mouse." If there's a yellow warning sign with an exclamation point in the middle next to your pointing devices, reinstall the drivers to get them to work. This is best done using the Windows Update utility in your "Start" menu's "All Programs" list. If driver installation doesn't work, then you may have hardware issues.
Hardware Issues
In the case of hardware issues, one option is to send your laptop in for a replacement if you want to use the pointing device again. Optionally, you can use an external USB mouse if the system recognizes it, but you'll then need to carry an external mouse with you everywhere you go.