How do I disconnect my internet connection from a computer?

Q Until recently, I have always been able to right-click the internet connection icon on my Windows XP PC’s Taskbar to disable my internet connection. I do this because I don’t like to leave the PC connected to the internet unmonitored for any length of time.

Recently, though, I find I am unable to do this. Instead, I get an error message that says: “It is not possible to disable the connection at this time. This connection may be using one or more protocols that do not support plug-and-play, or it may have been initiated by another user or the system account.”

The bottom line is that now, to disconnect the PC from the internet, I have to switch it off and restart it later – this is very inconvenient if I’m only away for 10 minutes.

I have tried to resolve this in various ways, including rolling back some recently installed drivers, but nothing has worked. Do you have any suggestions?
William Windsor

A This is one of those problems whose cause could be very difficult to trace. However, having researched the message it seems to have been traced back to the corruption of some files left by the Windows Update service.

Fortunately, the fix is pretty easy – either delete the corrupt files or rename the folder that contains them. This prompts Windows Update to rebuild the corrupt aspect of its database, fixing the error.

Here’s what to do. Launch Windows Explorer (hold down the Windows key and tap E) and navigate to the Windows installation folder: this will almost certainly be C:\Windows.

Now double-click the System32 folder (so you will be at C:\Windows\System32). Look for a folder called catroot2, being careful to avoid the one called catroot.

Now right-click the catroot2 folder, choose Rename from the pop-up menu and give it a new name (it doesn’t matter what, but we suggest catroot2OLD, to serve as a reminder. Now restart your PC and the problem should resolve itself.

If Windows displays an error message saying that it’s not possible to rename the catroot2 folder, you may need to stop the Windows service that’s making use of it.

To do this, click Start, followed by Run, then type cmd into the box before clicking OK. In the command window, type net stop cryptsvc and press Enter.

Rename the folder, then open another command window and type net start cryptsvc and press Enter. Rename the folder then open another command window and type net start cryptsvc and press Enter.