Drag by using MouseKeys

To move the pointer over the object you want to move or over the area you want to move to, press the arrow keys on your numeric keypad.
To hold down the mouse button, press the INSERT key on your numeric keypad.
To release the mouse button, press the DELETE key on your numeric keypad.

Notes

Make sure MouseKeys is turned on.
To change accessibility settings from Control Panel, click Start, point to Settings, click Control Panel, and then double-click Accessibility Options.
If MouseKeys doesn't function, press NUM LOCK, and then try MouseKeys again.
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.