You can configure your notebook PC to respond to wakeup calls from software programs and devices.
Some software programs respond to external events. For example, if you have Windows Fax and Scan configured to automatically receive incoming faxes on your computer, then Windows Fax and Scan runs its fax reception feature when it detects an incoming call.
Similarly, you may have devices on your network that require periodic access to your computer. For example, if you have a Windows Home Server machine on your network, Windows Home Server attempts to back up your computer each night.
If your computer is in sleep mode when an action is required, the program or device attempts to wake up your computer. ...