File type (un)association

Associate any unknown file type with Notepad++

Log files usually have the date of the log file as extension. You want to open them with Notepad++, but not by right-clicking the file and choosing Edit with Notepad++, but simply by double-clicking the file. Is that possible? Yes:

In the registry, go to:

• HKEY_CLASSES_ROOT\Unknown\shell
• add a key notepad
• under notepad, add a key command
• change the command key's (Default) string value in:
  • for 32-bit: "C:\Program Files (x86)\Notepad++\notepad++.exe" "%1"
  • for 64-bit: "C:\Program Files\Notepad++\notepad++.exe" "%1"
• now change the HKEY_CLASSES_ROOT\Unknown\shell key's (Default) string value in notepad (default is: openas)

Try to open any unknown file by double-clicking it: it's opened in Notepad++!

Tremendous!!!

source: How to open unknown extensions with notepad (microsoft.com)

Unassociate a file type

Once associated to a program, you cannot unassociate a certain file type/extension through the Windows Settings (or Control Panel).

It is however possible using the Registry Editor:

• open the Registry editor
• backup & delete the key HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.ext¹
• backup & delete the key HKEY_CLASSES_ROOT\.ext¹
• restart Explorer

¹where .ext is the file extension you want to unassociate/dissociate

source: How do you remove a default program association for file types in Windows 7? - Super User

tags

extension extensions unknown file type types