thanatoid wrote in :

Without going into everything you raised, I think using file
associations and hoping the right program will open is one of
the WORST practices MS has forced on us and I am astonished
that you have adopted it.

It's a brilliant idea. It's been sorely abused, usually by coders
who force associations on users against their will,
stealing existing ones from existing installs. So take control. FIGHT THE POWER!

There's no magic to them, I don't even use the OS's inbuilt
'Open With' dialog to set them up permanently.
I use the registry, every time. It's far easier.
The template below shows details, all that most stuff ever needs.
It is commented with lines beginning with a semicolon,
and these comments can follow active entries on the same line.
If you strip them out of the following template you'll see how little is needed.
It's all plain text, save as .REG and if some idiot coder steals your associations,
run the file like this that you keep, and it's yours again instantly.

I totally agree that lazy and arrogant coders who force their stupid will
instead of respecting remote host systems have borked this system for many,
it's why I deliberately took control of it. It really IS actually easier
this way than all that Open With nonsense, and trusting the shell tools to do it.


REGEDIT4

;Required, but extension can be anything, so long as the association it points to exists.
;Many extensions can use one association. Other associations may be set up, and switched here.
[HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\.asc]
@="LTspice"

;Optional, allows right-click to creat new data file anywhere.
[HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\.asc\ShellNew]
"NullFile"=""

;The association itself, with the descriptive name that the operator gets to see in normal use.
[HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\LTspice]
@="LTspice File"

;Sets path to executable, and addresses internal icon. Can also use path to external icon.
[HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\LTspice\Defaul tIcon]
@="E:\\EDITORS\\LTSPICE\\SCAD3.EXE,1"

;Commandline, allowing spaces in path and filename. Command arguments can be placed here.
;Escaped notation makes sure quotes and slashes work in registry.
[HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\LTspice\shell\ open\command]
@="\"E:\\EDITORS\\LTSPICE\\SCAD3.EXE\" -registry \"%1\""