If you have no mouse or not working properly you can use keyboard as mouse in windows 7 and xp both. By using a feature that is built in by windows, called MouseKeys you can use keyboard as mouse.
To turn on MouseKeys, go on Control Panel, click on Accessibility Options, click on the tab that says Mouse, and check the ‘Use MouseKeys‘ box. Alternatively, you could turn on MouseKeys by pressing Left ALT + Left Shift + Num Lock at the same time. Please note that this only works with the LEFT alt and shift, as if you try it with the right side, it will not work.
Here are the controls, provided that you have a numeric keypad, to run MouseKeys: