Registry: Unused file extensions

In Registry, if I click Fix, what will happen to files with extensions that are on the unused extensions list? I have many active files with extensions on the unused extensions list.

In Registry, if I click Fix, what will happen to files with extensions that are on the unused extensions list? I have many active files with extensions on the unused extensions list.

I think they are deleted. Make sure you do a backup of the entire registry before you do any fixing.

nothing will happen to the files themselves other than a disassociation with whatever program they're supposed to be linked to.

(for example deleting .mrc as a file extension wont delete my mIRC scripts, however it will delink them from mIRC as an "open" option :))

nothing will happen to the files themselves other than a disassociation with whatever program they're supposed to be linked to.

(for example deleting .mrc as a file extension wont delete my mIRC scripts, however it will delink them from mIRC as an "open" option :))

Why are they unused ?

I have only encountered "unused extensions" when :-

I have removed or un-installed an application or folder/file,

OR if it is a data file that is used by a portable application.

e.g. when I run something like VLC portable, Windows may decide to add an association for *.FLV,

but I never had any luck double clicking a FLV file and getting VLC portable launched.

I was ONLY able to play a FLV by launching Portable VLC first, and then selecting the file to play.

If the file association refers to something I have just removed,

or to a Portable Application data file,

I immediately purge it.

Otherwise I look for the cause before I purge.

Alan

I have only encountered "unused extensions" when :-

I have removed or un-installed an application or folder/file,

OR if it is a data file that is used by a portable application.

Create a file called my.fred

Do a right-click on the file to bring up the context menu ... nothing more.

That action alone (in XP at least) is enough to create a .fred file extension entry in in the registry!

Files are created with all sorts of extensions for all sorts of reasons ... it doesn't take much for unusual extensions to get added to the registry.

Create a file called my.fred

Do a right-click on the file to bring up the context menu ... nothing more.

That action alone (in XP at least) is enough to create a .fred file extension entry in in the registry!

Or click on a Windows file that isn't actually used by a program other than Windows, eg click on a prefetch file and this will show up .pf as an unused file extension in CCleaner (or any other reg cleaner)

Create a file called my.fred

I just can't resist! my.fred files, that's hilarious. :lol:

From edpb, many thanks to all who replied to my question about possible CCleaner actions when cleaning items from its "unused file extension" list. There are many such items, and many are not really unused, so until I get more experience with this I will just uncheck all of them and let them be.