There could be many reasons like hardware conflicts, improper drivers, USB port problem etc. I had googled and found the following sites useful, please have a look: daniweb eggheadcafe codingforums virtualdr tweaktown techsupportforum techguy cybertechhelp Please let us know if you found the solution. :)

I found this in Help and Support. In the Control Panel open Accessibility Options Icon and click Mouse Tab and than Setting. To move the mouse pointer by using MouseKeys If you have not already done so, turn on MouseKeys. To turn on MouseKeys, open Accessibility Options, click the Mouse tab, and then select the Use MouseKeys check box. Use the buttons on the numeric keypad to move the mouse pointer. If MouseKeys doesn't function, press NUM LOCK, and then try MouseKeys again. To move the pointer horizontally or vertically, press the arrow keys on your numeric keypad. To move the pointer diagonally, press HOME, END, PAGE UP, or PAGE DOWN on your numeric keypad. Notes To open Accessibility Options, click Start, click Control Panel, and then double-click Accessibility Options. To specify whether NUM LOCK must be on or off for MouseKeys to function, on the Mouse tab, click Settings, and then for Use MouseKeys when NumLock is, click On or Off. To change the pointer speed and acceleration when using MouseKeys, on the Mouse tab, click Settings, and then move the sliders to adjust the pointer speed and acceleration. To temporarily increase or decrease the pointer speed, on the Mouse tab, click Settings, and then select the Hold down Ctrl to speed up and Shift to slow down check box. cg

Doing a power cycle should sort that. 1) Make sure the touch pad is enabled (still not working? Go to step 2) 2) Turn off the computer 3) Unplug the power cord from outlet or laptop 4) Remove the battery 5) Press and hold the power ON button for 30 seconds 6) Re-insert battery 7) Plug in power cord 8) Turn on the computer After doing the above is it working? Paddy..

'Make sure the mouse is plugged into the correct port or port-type. You may try re-booting w/o the mouse and then plugging it in again afterwards to be sure it is picking up the correct accessory." If this is a wired mouse... ---> If it has a round connector, that's a PS2 connector, and the computer must be turned off when it's plugged in. Then turn it on and boot up. Or, if the machine is already on when you plug in a PS2 mouse, you'll have to restart (reboot) it, in order for the mouse to be recognized. ---> If it has a flat, USB connector, it can be plugged into any available USB port; and the machine can be turned on when the mouse is plugged in. USB equipment should be recognized right away when it's plugged in. As Dilly_Dally said, you probably should go into Control Panel and click on the icon for "Mouse" and make sure all of the settings are correct. Also, bear in mind that when an external mouse is plugged into a laptop, it doesn't automatically disable the built-in touchpad on the laptop. If your thumb, or shirt sleeve, etc., brushes across the touchpad, that will affect what the pointer does and where it ends up.