Unused file extentions

When scanning the registry there is huge list of unused file extentions listed which I have never bothered to do anything about as I am unsure of what might happen if I remove them.

I would appreciate an explanation of why the are listed and what if anything I should do.

I have been using CCleaner for quite a while now and have managed all the other sections without any trouble so far.

When scanning the registry there is huge list of unused file extentions listed which I have never bothered to do anything about as I am unsure of what might happen if I remove them.

I would appreciate an explanation of why the are listed and what if anything I should do.

Yes I get a few of those when I do a Registry scan. ppi, ase, cin, cr2, crmlog, crw, crw, dmp, dng, exr, hdr, jsx, jsxbin, loaded, mnu, mos, mrw, orf, pbm, pdd, pef, psb, pxr, raf, shh, sta, tmp and x3f.

I know were loaded came from so I'm not bothered about that one. They are probably apps you've had installed and when you uninstall them they were left behind in the registry. All these aren't common Windows file extensions so you can remove them all. Just make sure you make a backup of what it removed, just in case. ;)

As far as I know it doesn't mean that these file extensions are unused (perhaps a slightly misleading term). After all CC doesn't scan your entire disk just to see iif you have a .xyz file hanging around. I think it means that there is a registry entry for these extensions but it is not associated with any program. You may well have hundreds of them, if you attempt to open one then Windows will ask 'What with?'.

I used to have quite a few, some with very peculiar extensions. After a rebuild I have none, and if any do pop up from time to time I remove them, with no ill effect so far.

Windows loves wasting time, and this is one of its stupid habits.

I only have to create a junk file called junk.jnk, and even if I immediately delete it Windows will obsess about *.jnk,

wanting to know what to do with it should I double click on it.

The same stupidity occurs with *.odt, and in fact with any Open Office extension,

because I use Portable Apps version of Open Office to conserve disk space and avoid registry junk.

When I launch Open Office it records the registry keys it will take over and then I can access *.odt etc,

Windows immediately takes notice and records somewhere the fact that *.odt is a significant extension,

and that a double click should use Open Office to process that file.

At that stage Windows knows of this extension, and it is NOT unused.

When I close Open Office its tidy-up procedure is to :-

move relevant things into its own *.ini file ;

restore the system back as it was, which includes the keys it had taken over.

Unfortunately nosey parker Windows still remembers that *.odt is a relevant extension,

but it has forgotten what to do with it.

I have no qualms at all about ill effects of deleting unused extensions,

but I am always (almost) alert to any possible evidence of a Windows hiccup to fix, or of a malware intrusion,

so I simply scan the lists of files and registry keys selected for deletion to see if something new has happened,

and then they get purged.

Alan

I would like to warn you to be as cautious with "unused file extensions" as I hope you are with registry cleaning. I have learned the hard way that clearing CC's list of what it deems "unused" trashes most of my file associations. I didn't learn this the first time, it took 2 cleanings for me to realize what had happened. I had to spend hours fixing file associations, not once, but twice. So - unless you know for certain - what that file extension was associated with, I suggest leaving it alone.

questions remain open:

1) does removing unused file ext. slow down the system when you don't delete these? Or to put it another way, does deleting genuinely useless file extensions

actually speed up my system?

2) is there a risk that leaving any old/unused extension in the registry compromise the security in any way, so that hackers may use these to interfere...?

And if the answer to both is NO, then this feature of cCleaner is pointless.

Any comments?

1) No to both parts. Actually the first part was illogical, Jim.

2) I doubt that hackers would be in the slightest bit interested in unused file extensions.

And the final answer is that this is the whole point of CC, removing unwanted and unnecessary elements.