CCleaner bug: breaks OpenWith... in WinXP, Vista, Win7

Hi all,

I've been a CCleaner user for years, and have only recently discovered what appears to be a bug in CCleaner. It appears to somehow be corrupting the registry so that the explorer "Open With..." feature that appears on the right-click of most files...well it doesn't really work any more. Seems to be pretty reproducible, and I've noticed (through a lot of googling) that other people who experience this problem seem to have these situations in common:

  • WinXP Pro, Vista Pro, Win7 Pro
  • 32 or 64 bit processors
  • Have used CCleaner

This is just a suspicion, not a confirmed bug report.

Here are the symptoms:

  1. For any file type, the "Open With..." explorer menu item is there, but it never offers up a list of programs to use (in other words, the submenu doesn't appear), even when there is a valid list of programs (OpenWithList or OpenWithProgids) for that file type in the registry
  2. If you select the "Open with..." item, you are offered the wizard for adding programs to the OpenWith list (this is correct), but the file name is corrupted with an " after the file extension, like this: foobar.txt"
  3. By using that wizard, you will be creating a new extension (in the example, .txt" in the registry and building a new set of OpenWith lists there
  4. Even after you've done this, issue #1 persists: you are not offered the Open With list as a submenu; consequently, you have to go through the open-with-list-builder wizard each time

I've spent a lot of time inspecting all the parts of the registry that are supposed to handle this feature, but I've not found anything obviously out of order.

Anybody else seeing this?

I'm happy to fix the registry myself if I only knew where to apply the fix.

Thanks in advance for any info / hints you can provide.

it sounds like you may be blindly removing all "issues" which appear in ccleaner's registry section. This will cause this to happen.

Are you by any chance doing this especially with the files extentions section?

if so please follow the advice in my signature. Did you make registry backups?

mmmmh, when i create a file without an fileextension, than rightklick with mouse and kontextmenu "openwith.." there is no "open with..." but all other is ok by me.

but I had a similar experience with an earlier version of ccleaner. as i installed an older version of acdsee, than run ccleaner and it found many of "unused fileextensions". after cleaning was my acdsee complete out of my xp and i must reinstall a few times, until i decide to disable the "unused fileextensions"

but in newer version is not that happened... :)

Using XP Pro myself and noticed my Open With list was out to lunch the other day when needing to assign an extension to also open in another program, and I know it worked months ago the last time I used it. I however worked around it by going into 'Folder Options -> File Types'

Are we sure it's CCleaner's fault, and not some monthly Microsoft Update that has caused it?

by me there are maybe about 20 fileextensions without extensions :wacko::D -but it works well without problems... :)

Ok, I've figured this out on my system at least:

* XP will gladly offer the 'Open with' right-click option if it's a file type already registered and known by the system, such as a .txt text document.

* XP will not offer the 'Open with' right-click option if it's a file type that is not registered and not known by the system.

Perhaps that is just how Windows is rather than being CCleaner induced.

"Open With" is missing for non-assigned filetypes (eg no extension) however clicking open brings up the equivalent prompt anyway, but I am unsure as to whether or not this is the deault windows behavior.

Windows 7 Pro Sp1 X64

It does identical on XP.