http://support.microsoft.com/kb/269155
- Click Start, click Run, type cmd.exe, and then press ENTER.
- Type set devmgr_show_nonpresent_devices=1, and then press ENTER.
- Type Start DEVMGMT.MSC, and then press ENTER.
- Click View, and then click Show Hidden Devices.
- Expand the Network Adapters tree.
- Right-click the dimmed network adapter, and then click Uninstall.