Ok... For anyone like me who can't live without knowing "why", here is what
I have found:
AutoCAD will always reset the file association of DWG files every time you
open it.
So, if you open MDT and close it, DWG files will now be opened by MDT when
you double-click on them in explorer.
If you then open ADT and close it, DWG files will now be opened by ADT when
you double-click on them in explorer.
The Problem: If you have ever used the "Open With" option in Windows 2000
or XP to change who opens DWG files, that seems to completely override the
normal file associations AutoCAD sets up. I think this is where the
confusion is.
To allow the last AutoCAD session opened have complete control over opening
DWG files, delete the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExt
s\.DWG
It's harmless to delete the whole key, but all you really need to delete is
the "Application" value. This value may not always exist. AutoCAD does
NOT create or use this key.
Here is how I believe Windows determines which program opens a file:
1) If the "Application" value above exists, then it uses that to open the
DWG. (Win2k and XP only)
2) If the above key is NOT defined, then use the "Classic" method that is
setup by AutoCAD:
a) Look for HKEY_CLASSES_ROOT\.dwg\(default). (thats a DOT dwg)
...The "Default" value is normally set to "AutoCAD.Drawing.15".
b) Now, look for
HKEY_CLASSES_ROOT\AutoCAD.Drawing.15\Shell\Open\Command\(default)
...In my case this was set to " "C:\Land Desktop 3\acad.exe" "%1" "
If you have two versions of AutoCAD on your system, open and close 1 of
them, and then look at that registry setting.
Now, open the other one, use F5 to refresh the REGEDIT view, and look at the
Command setting again. You will see that it changes to the last one
opened every time.
Hope that helped a bit.
Chris
"Mark Taylor [Autodesk Support]" wrote in
message news:1D1594EDEC3F697D5A81566FA04C77E7@in.WebX.maYIadrTaRb...
> OK, after a little more investigation, unless you customise the file
association it will default to the last installed application.
>
> I did edit the associativity via the Change button in the Folder Options
dialog, but this seemed to have no effect. So I used the
> Restore button within the Folder Options dialog, and then used the
Advanced button, and customised the Launch AutoCAD action from
> within the following dialog. This did work, so it seems there is an issue
with using the Change button rather than Advanced.
>
> --
> Mark Taylor
> Product Support, EMEA
> WW Support & Services, Autodesk
> Discussion Q&A: http://www.autodesk.com/discussion
>
> "Mark Taylor" wrote in message
news:FC2D61B821833FE7FAED9ED978FC0FE7@in.WebX.maYIadrTaRb...
> > I have the same problem with Window's XP, in that Land Desktop always
opens the drawing I double click.
> >
> > Yet I have a colleague whose machine (on Win 2000) always follows the
logical behaviour i.e. the last product to run grabs the DWG
> > file association. He is also able to edit the extension and it will
change to suit.
> >
> > I will research some more on my machine, and let you know if I make any
progress. Maybe this is symptomatic of registry
> corruption.
> >
> > --
> > Mark Taylor
> > Product Support, EMEA
> > WW Support & Services, Autodesk
> > Discussion Q&A: http://www.autodesk.com/discussion
> >
> > "raymondp" wrote in message
news:f0d173a.1@WebX.maYIadrTaRb...
> > > Mark,
> > > No,even after I run Autocad double clicking runs MDT. Mabe if I
uninstall/reinstall Autocad, it will be the last product
> > installed?
> > >
> > > What I don't understand is that resetting the file acc in explorer is
not having any effect. Where is this in registry?
> > >
> > >
> >
> >
>
>
