The solution to restore the Open With choice depends upon the operating system:
Windows NT 4.0
To restore the Open With choice on a right click, open a CMD prompt and type:
where .xxx is the file extension.
NOTE: See tip 0482.
Windows 2000 can support multiple Open With choices per file extension. The choices are configured per user, at the following key:
Each file extension that has an Open With choice has a .xxx sub-key. The .xxx sub-key has a OpenWithList sub-key, yielding the following registry path:
The OpenWithList sub-key has a string (REG_SZ) value name of MRULIST which contains a list of one character Value Names, one for each unique program. Here is an example of the .htm extension on my workstation:
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.htm\OpenWithList a REG_SZ iexplore.exe MRUList REG_SZ acfbehgd b REG_SZ WINWORD.EXE c REG_SZ notepad.exe d REG_SZ Acrobat.exe e REG_SZ FRONTPG.EXE f REG_SZ agent.exe g REG_SZ EXCEL.EXE h REG_SZ POWERPNT.EXEWhen deleting one of these one character value names, you must remove it from MRUList. If you delete the last entry in the MRUList, delete the entire .xxx sub-key.
NOTE: The sequence of the characters in the MRULIST is the sequence of the apps you see in the Open With dialog.
NOTE: If you create a new .xxx sub-key by checking the Always use this program to open these files box, the .xxx sub-key receives an alphabetic character value name with a string of ProgramName.exe.
NOTE: If you hold down the shift key as you right-click a file, the Open with choice is added to the context menu.