Use keyboard as mouse & mouse for on screen keyboard

Use Keyboard As Mouse

When mouse isn’t working properly, this trick can be very helpful. To activate mouse keys all you do is press Left Alt+Left shift key + NumLock and click OK or press enter.

Use the Numerical pad for controlling the mouse pointer.
5 is for click.Other numbers are for moving the cursor.
+ is for double click
- for right click

On Screen Keyboard

On screen keyboard is one of the coolest windows features that displays a virtual keyboard on thecomputer screen that allows people with mobility impairments to type data by using a pointing device or joystick.

To use it go to start-> run and type osk