Copernic problem: Indexing kernel cannot be initialized

I use Copernic Desktop Search quite a lot at work - it's very useful since I can search through all the documents on all the network shares I can access, and it's much quicker than Outlook for searching through my emails. This morning, it stopped working, and just displayed "No matches found" no matter what I did. Turning on logging, I was given the cryptic message "Indexing kernel cannot be initialized. Please contact our technical support team. Error = 80004005". I contacted Copernic technical support, and got this back:

A. Make sure to close your Desktop Search application.

To exit your Desktop Search application: right-click its tray icon (next to your computer clock) and select Exit.

B. Locate your Index folder.

1. Open Windows Explorer or double-click the icon "My computer".
2. Browse to your index folder.
Unless you modified the index location, by default this folder should be in one of these three locations:
* "C:\Documents and Settings\%UserName%\Local Settings\Application Data\Copernic\"
* "C:\Windows\Local Settings\Application Data\Copernic\"
* "C:\Windows\Profiles\%UserName%\Local Settings\Application Data\Copernic\"

For Windows Vista:
* "C:\Users\%UserName%\AppData\Local\Copernic"

If you can't find your index then make sure you can see hidden folders.

1. Open Windows Explorer or double-click the icon "My computer".
2. Select the Tools menu then click Folder Options.
3. In the Advanced settings section of the View tab, select the option "Show hidden files and folders".
4. Try to locate your index folder once again.

C. Select and erase the folder named "DesktopSearch2".

Right-click the folder and click Delete to erase it.

D. Restart your Desktop Search application and recreate your index.

1. In your Desktop Search application, click on Tools.
2. Click Update Index.
3. Click Entire Index.

Make sure to use the latest version. You can find it on our web site: http://www.copernic.com/en/products/desktop-search/download.html.

NOTE: this version can be installed over your current version. There is no need to uninstall. Note also that simply updating the version will not fix this error. Your index has to be deleted as instructed.

And it worked!

Posted here not because it's particularly interesting, but because there were no Google results for the failure code, and it might save someone a couple of hours waiting for a response from Copernic technical support. Who were very good, incidentally - I got this back about five hours after I emailed them at eleven, London time.

And the cause of the problem? I strongly suspect that indexing the C:\ drive was a bad idea. The indexing kernel started failing again after I rebuilt the indexes, but stopping it indexing the C:\ drive has produced a working copy of the index.