Laptop Assistance

[Richard O'Neill]

  I have a Del laptop running Win 7. After 15 minutes of no keyboard or 
mouse inputs the computer promptly goes to sleep. This is a PITA which 
requires me to reenter a password.
Since the machine is always connected to wall power I would prefer this 
didn't occur but don't know how to change it to 'ON', all the time. Does 
anyone know if it's possible?
If so, how do I reconfigure it? Control panel is of no help.

  I suppose I could rig a electromechanical device to tap a key every 10 
minutes or so but that seems far too much like a 'steam punk' solution 
for me.

Richard