How can I set the value for each default key in different subdirectories of regedit?

Question

Here is a screenshot what I'm working with:

screenshot of regedit directory

I wanna run a script that will set every default key in each subdirectory named mplayerc64.*\shell to "enqueue" (no quotes)

Answer 1

PowerShell:

Get-ChildItem Registry::HKCR\mplayerc64.* -Recurse |
  Where PSChildName -eq 'Shell' |
Set-ItemProperty -Name '(Default)' -Value 'enqueue'  

Aliased:

gci Registry::HKCR\mplayerc64.* -s | ? PSChildName -eq 'Shell' | sp -Name '(Default)' -Value 'enqueue'

Answer 2

1. Export the Registry key and subkeys as one .reg file, e.g., no_def.reg.
2. Open in the.reg file in a text editor, such as Notepad or Notepad++.
3. Manually, or by search-and-replace, insert `@="enqueue" after each key.
4. Check carefully for errors -- a mistake in a Registry entry can cause immense problems.
5. Save the .reg file under a differe4nt name, enq.reg.

Now you can apply the new .reg file, see if it works as needed, and can revert to the original settings using the first (unmodified) exported file.

N.B. Massive Registry changes can cause issues. Make a disk image, to be safe, before making these changes.