Shoutbox

I scanned my registry for errors and the following key in the HKLM\Software root was detected as unnecessary/corrupt:


I tried to manually delete it using regedit but Windows does not allow showing the following:


So I tried various registry scanners/cleaners without success (they're unable to delete it even though they detect it as corrupt).
I also tried doing it in Safe Mode without success.
Any ideas? Thanks
NOTE: I'm running WinXP Pro SP3 with full administrative rights