latest ccleaner detects this below after registry scanning but never fix it although it says it done when push Fix It button.
Unused File Extension {80b8c23c-16e0-4cd8-bbc3-cecec9a78b79} HKCR\{80b8c23c-16e0-4cd8-bbc3-cecec9a78b79}
this above seems to be like a virus which usually rename folders to folder-name.EXE while folder become hidden for explorer (however treesize or other explorer-like controls are able to see them properly - this is a kind of new virus or whatelse dramatically affect the whole os windows xp and others.
the main issue is that the registry element grabbed by ccleaner as above can not be deleted by ccleaner or manually.
the final fixing for a better ccleaner should consider to delete that registry element before operating system starting in order to avoid os locking for that but also giving the user the possibility to see what are the files locked or which locks that registry record.
On the other hands that registry error above seems to be concerned with the new error provoked in the os that no more allow some applications to run, meaning the user receive the error message like this
{The application failed to initialize properly (0xc0150004)}