Windows XP gives you the option to work without mouse (with Keyboard only)
Press ALT+Shift+Num Lock
You will hear a beep and then you can see windows asking for using MouseKeys. Click OK.
You will see mouse like tray icon if it is crossed like this then press Num Lock again.
Now use the Numeric Keypad to move cursor around.
8 key for Up,2 for down,4 for left, 6 for right
When you want to use the Left click of mouse Press 5. For right click you can this key on the keyboard
Note: The cursor moves very slow but you can speed it up. By pressing ALT+Shift+Num Lock you will see a dialogue click on settings again click settings, and then select Hold down Ctrl to speed up and Shift slow down. Now when you want to move cursor then hold Ctrl and then press any key to move the cursor through numeric keypad. It will speed up now.