Avira, unused file extension

[stuck]

Recently I noticed that ccleaner always found the same unused file extension when I ran a registry scan, specifically:
Unused File Extension {80b8c23c-16e0-4cd8-bbc3-cecec9a78b79} HKCR\{80b8c23c-16e0-4cd8-bbc3-cecec9a78b79}

Further, ccleaner's fix this issue option, didn't. Copying and pasting the above line into Google turned up some curious stuff:
http://www.google.co.uk/search?q=Unused ... ec9a78b79} why doesn't that work as a link?

In summary:
- this key is added to the reg. by Avira
- no one at Avira will say what it does, the most detail they've give is it's needed for internal purposes
- a thread on Avira's own forum implies it has something to do with the Avira notifier contacting Google
- ccleaner can remove the reg. entry but first you must untick the 'protect registry settings' in the Avira control panel

I removed this reg. keya couple of days ago and as yet the sky hasn't fallen in. Avira still updates and still gives me the splash screen when it does and as yet the reg. key hasn't come back.

Ken

[Argus]

Copying and pasting the above line into Google turned up some curious stuff:
http://www.google.co.uk/search?q=Unused ... ec9a78b79} why doesn't that work as a link?

Hi Ken,
Explained in the Test Area, here.
Use this link: http://www.google.co.uk/search?q=Unused ... 9a78b79%7d" onclick="window.open(this.href);return false;