I recently solved this issue and wrote a procedure for my IT team on this, related to Windows power management of the NIC's. Setting the BIOS to accept magic packets is one thing, for sure, but preventing Windows from putting the NIC to sleep is often overlooked, and it is easy to deal with, as follows:
Steps to Disable NIC Power-Saving Features to Keep the NIC Awake
by Dan Reams
These steps are based on my experience and not by any one article read in the MS Knowledge Base or on the forums.
• Explore the power-saving properties of the NIC’s via their driver controllers (properties tabs) and de-select “Allow this computer to turn off this device”. You may have to hunt for this, in Windows XP, via right-clicking on the NIC, in Device Manager, or navigating to the NIC properties via the Network control. In Windows 7, there is often a “Power Management” tab associated with the NIC upon right-clicking the NIC’s properties via Device Manager. Related:
o Disable “Allow computer to turn off this device to save power”
o Windows 7 shuts off my network adapter when i the computer goes into - Microsoft Community
• Implement a catch-all registry setting value to over-ride any hidden “on” state of the power-saving feature. One can certainly navigate to the registry and create or edit keys, but I prefer to create registry files (.reg), for each NIC, and simply double-click them. This both avoids real-time typing mistakes and is much faster. In the below example, the 0001 represents NIC #1 in the system. If the system has multiple NIC’s, you should also create a .reg file with a value of 0002 in the same position.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}\0001]
"PnPCapabilities"=dword:00000038
Simply copy and paste the text above, to a text file, save it, and rename the file from .txt to .reg, then run it on the target PC’s. Again, if the PC has two NIC’s, create a version of the file that replaces 0001 with 0002 and run that as well.
