Windows goes through a laborious means to close these connections and log off users before it completes the shutdown. Yes, even on a stand-alone machine.

Right click on Network Neighborhood and choose properties and check your network settings. Don't modify this area unless you know what you're doing, but if duplicates of known network hardware exist edit (remove). If you get scared, be sure to press 'cancel' or else you get to do the Bill Gates shuffle.

If you mess up your internet connection.

Remove everything from the properties, then allow the computer to reboot and reinstall fresh i.e. rip-n-strip. Feeling lucky? Rip-n-strip it. For stand alone machines, set the Primary Network Logon to Windows Logon to avoid the login password routine.

If everything caves, go to Startup screen (press and hold the Ctrl button while machine is rebooting), choose DOS prompt and use 'scanreg /restore' to restore old configuration.

Wheee.. a 25 year PC veteran.