Using the below steps will allow you change your computer's power settings. For example you will be able to have your computer never go into sleep mode.

Windows 7

• Log on to your computer as an administrator.
• Click Start menu and then open Control Panel.
• Select Power Options.
• Click on Change when the computer sleeps.
• In the Put the computer to sleep dop-down menu select the appropriate option.

Windows XP

• Log on to your computer as an administrator.
• Click Start menu and then open Control Panel.
• Select Performance and Maintenance.
• Select Power Options.
• On the Power Schemes tab find Power Options Properties.
• Select the Power schemes drop-down menu and select the appropriate option.