And just to confuse you a bit
LOL!
BTW, Very nice one and informative for those interested, David.
Jentle Jiant, You may also try ShellExpert utility.
--
Ramesh, Microsoft MVP
Windows XP Shell/User
http://www.mvps.org/sramesh2k
Windows 2000 Group Policy Registry Table:
http://www.microsoft.com/windows2000/techinfo/reskit/en-us/gp/gpref.asp
File associations are a cascading thing. With up to 25 seperate settings overriding each other.
A ProgID (Program ID) is the name that appears as the default value for the extension.
EG
HKCR\.mp3
Default Value = <the ProgID>
You look the progID up at
HKCR\<progid>
eg
HKCR\WinAmp
It may have a ClassID (CLSID) as well (As Word.Document will), usually a subkey of the ProgID, maybe something like this
HKCR\WinAmp\CLSID
Default Value = {some long number}
Plus there are the backup associations (the SystemFileAssociations I mentioned earlier)
User settings are stored under here (What you've picked from the Open With dialog)
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts
There are some special ProgIDs
* is for All Files
Unknown is for all files not registered
AllFileSystemObjects is for all files and file folders
(there are more like AudioCD but aren't relevent for this)
And just to confuse you a bit
Most of these are Per User or Per Machine (99%), but the HKCR key shows a merged view of User/Machine settings as HKCR doesn't really exist but is a merge of HKCU\Software\Classes and HKLM\Software\Classes. User overrides machine if the keys/values are identical else they are merged if not.