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I inadvertently set the Registry Editor to be the default editor for *.txt files. Now when I go to change the default, "Always use this program to open these files" is grayed out. This is the case whether I right click on the file and choose "Open with...", or start with the "Set Default Programs" control panel.

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Why? How can I fix this?

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Is it grayed out just for notepad, or for all programs? –  nhinkle Jun 17 '10 at 6:20
It's grayed out for all programs. –  Herb Caudill Jun 18 '10 at 19:14

5 Answers 5

Assuming you are logged in as Admin, first thing to check is the Windows Registry.

  1. Open Registry Editor (Start > Run > regedit) and navigate to


  2. In the right side of the screen double click on "NoFileAssociate".

  3. Change the value of "NoFileAssociate" from 1 to 0.

  4. Now navigate to


  5. Repeat steps 2 and 3.

  6. Close "regedit" and reboot your machine.

If the above procedure doesn't work for you (or if you already have "NoFileAssociate" values as 0), reboot in safe mode and change a filetype to be opened with a default program (or right-click and select "open with" for that file type, and check if the box is still grayed out or not) and hit OK. In the next reboot, the issue should be fixed.

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Use this file association fixer tool



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That worked like a charm - thanks so much. –  Herb Caudill Jul 4 '10 at 1:24
You are welcome –  Moab Jul 4 '10 at 15:16

Check If you've unticked the hide file extensions for known file types In the folder options. You may have this unticked and when renaming a file you also removed Its extension.If you know the file type and add the extension (eg .doc for word) the option shouldn't be greyed out anymore.

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Having an unknown extension doesn't do what you say. Try opening a command line, go to your desktop folder and do echo rats > rats.rats. Now go to your desktop and double click. –  Isaac Rabinovitch Nov 24 '12 at 20:14
up vote 18 down vote accepted

I came across this problem again, but in this case the file association fixer tool suggested by @Moab didn't work because it only handles a handful of common extensions, and the extension I was having trouble with (.ahk) isn't included.

I did some more digging and found a general solution using regedit; this did the trick for me.

  1. Open regedit
  2. Go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts
  3. Find your extension
  4. Delete the UserChoice key
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Thank you!! Now I just wonder how the heck this happend in the first place. –  thnee Jul 19 '13 at 20:08
This happened for me just after using mplayer to open a file of the same type. Might be a coincidence though. –  persiflage Jul 4 '14 at 11:43

In case anybody is still having this issue, it's worth checking if you have the File Association Helper installed. It's included as a part of the WinZip package and overrides the default settings for how you deal with files, resulting in the greyed out "always use this program" box. Just uninstall it and it will go back to normal.

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protected by Community Dec 22 '14 at 20:44

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