Category Archives: Windows

Windows stuff and related..

Getting Devcon.exe onto and working with Windows 7

The DevCon utility is a command-line utility that acts as an alternative to Device Manager. Using DevCon, you can enable, disable, restart, update, remove, and query individual devices or groups of devices.

Download the “Windows Driver Kit (WDK) 7.1.0  from Microsoft:

Extract the ISO to a temp directory with WinRAR, Uniectractor

Extract the install file “WDK\setuptools_x64fre.msi” to a temp directory, where you will find “WinDDK\7600.16385.win7_wdk.100208-1538\tools\devcon\amd64\devcon.exe”

Note: devcon MUST be run from an administrator cmd win.


Windows disable USB power saving (DisableSelectiveSuspend)

This is handy for disabling the power scheme that may take your USB device offline at the most annoying times e.g. a USB fingerprint reader for Imprivata’s workstation sign on going into power-save mode will fail since the device failed to return from power saving mode.
This can also be set via registry settings and eventually by a GPO —
This procedure describes how to modify the following registry setting:
Entry: DisableSelectiveSuspend
Value: 1 disables selective suspend mode. 0 enables selective suspend mode.
  • This procedure may reduce the battery life on a portable computer.
  • This setting affects all USB host controller drivers in the system. If the value of the DisableSelectiveSuspend registry entry is set to 1, selective suspend mode is turned off. Additionally, the Allow the computer to turn off this device to save power check box does not appear on the Power Management tab for the USB root hub.
  1. Click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following registry subkey:
  3. On the Edit menu, point to New, and then click Key.
  4. Type USB for the name of the subkey, and then press ENTER.
  5. Click the following registry subkey:
  6. On the Edit menu, point to New, and then click DWORD Value.
  7. Type DisableSelectiveSuspend for the name of the DWORD, and then press ENTER.
  8. Right-click DisableSelectiveSuspend, and then click Modify.
  9. In the Value data box, type 1, and then click OK.
  10. Exit Registry Editor.


1. In Power options, click Change advanced power settings.

2. In the Power Options dialog box, expand USB settings, and then expand USB selective suspend setting.

3. If you want to enable Windows 7 to turn on the USB root hub when the computer is running on battery power, click Disabled in the On battery list.

4. If you want to enable Windows 7 to turn on the USB root hub when the computer is plugged in to a power outlet, click Disabled in the Plugged in list, and then click OK.


Troubleshoot Power Management Settings in Windows 7

Windows Vista includes a command line tool, Powercfg.Exe, that you can use to configure power management settings. Windows 7 introduces a new switch, /energy, to provide a comprehensive report of those settings. It also offers diagnostics that can indicate which applications or devices might be causing power management issues (such as a USB driver not entering suspend) and what power management settings you can configure differently for better results. At an elevated command prompt, simply enter:
POWERCFG –ENERGY –OUTPUT <path\filename>
The tool will observe your computer for 60 seconds, and then create a file called ENERGY-REPORT.HTML in the path you specified. Simply double-click on this file to see what’s going on.