XP (
http://forums.techarena.in/tips-tweaks/1161554.htm)
1. Click Start. Click Run. Type cmd and press OK.
2. Type "set DEVMGR_SHOW_DETAILS=1" (without quotation marks) and press Enter.
3. Type "set DEVMGR_SHOW_NONPRESENT_DEVICES=1" (without quotation marks) and Press Enter.
4. Type "start devmgmt.msc" (without quotation marks) and click press Enter.
5. Click View. Click Show hidden devices.
Vista/W7 (
http://forums.techarena.in/customize-desktop/1141528.htm)
1. Go to start menu > My Computer > Properties.
2. On the left click Advanced System Settings.
3. You will now see a System Properties window automatically opened to the Advanced Tab, Just click the Environment Variables button located at the bottom.
4. Under User Variables click New
5. Create a Variable name called devmgr_show_nonpresent_devices With a Variable Valve of 1. Click OK when Done.
6. You will now see this entry appear under your User Variables at the top, Once you confirm it has been entered correctly just click OK on the Environment Variables Window then again on the System Properties Window.
7. Open your Start-Menu again and right-click Computer and open Manage
8. Select Device Manager found on the left, then at the top click View > Show Hidden Devices.
From here, you can now expand either Human Interface Devices, Universal Serial Bus controllers, or Unknown Devices. You will see both full contrast images (currently plugged in devices) and faded images (built enumeration profiles not in active use). I'd remove Logitech entries for any wheels you have plugged in (right click-uninstall OR just delete them), unplug the wheel, then replug in to a different port. If you get unknown devices, you can determine if it's a Logi product if the Hardware ID (Under Details and pulldown menu if you doubleclick a device) has a "046d" string in the VID_PID area.
When you unplug/replug the wheel after doing this, it will force windows to create a whole new driver profile for the USB enumeration that just occured, which can and will resolve many of the issues listed in here. It may also resolve the off-center calibration according to the software, as the calibration in this device is determined by Windows and DirectInput. If the product goes to dead center after doing it's spinning dance, then the hardware is calibrated. It's possible that even after calibration, the Windows has incorrect calibration data within DirectInput. To clear this out, repeat the above steps BUT don't unplug/replug the wheel, go to the Logi download page for either the G25 or G27, download the Clear Calibration utility, run that, then NOW unplug and replug the wheel. Clear Calibration will remove additional information that Windows stores as it's own calibration in DirectInput.
