Troubleshooting Sleep Mode Device Wake-Up with Powercfg
The use of sleep mode allows you to conserve power by forcing an inactive workstation to reduce processing power, shut off hard drives, and disable video output. Enforcing an organization-wide power saving policy on workstations can be very budget-friendly and aide in “green” efforts.
A potential problem with putting workstations to sleep is that not all devices are capable of waking up. When a workstation goes to sleep it does minimal processing and stops all hard-disk I/O. In order to properly wake up a device has to recognize that the computer has gone to sleep, and that it should recognize the wake up procedure rather than expecting a full boot sequence.
The powercfg utility, newly updated as of the release of Windows Vista, contains a great function for troubleshooting this. We can output a list of all of the system devices that support sleep mode by typing the following command: powercfg –devicequery wake_from_any.
If your workstation is not reinitializing your NIC or sound card after going into sleep mode then you will want to ensure that it is in this list. If it’s not, there is no need to panic. The ability to recover from sleep mode is typically a feature of the hardware driver. This means that rather than purchasing new hardware you can simply update or replace the driver on your system!