HELP! XP is not shutting down anymore on X30

[CyberDude]

For some reason XP is not shutting down anymore. After I click 'turn off' the icons dissappear leaving nothing but the wallpaper and then it hangs. The mouse and keys don't work forcing me to turn it off by the I/O button.

The event viewer has an warning reported under apps which says

Windows saved user userdirectory\username registry while an application or service was still using the registry during log off. The memory used by the user's registry has not been freed. The registry will be unloaded when it is no longer in use.

This is often caused by services running as a user account, try configuring the services to run in either the LocalService or NetworkService account.

How can I find out which service is causing the problem? I doubt that thois is the cause of my problem though.

Also, in my firewall logs I noticed a 'new' file trying to access the internet. ANC.sys in the system32\drivers directory. does anyone know what this file is? I searched for it in google and game up with nothing.