How do I control which version is used to open a .DWS file?

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How do I control which version is used to open a .DWS file?

Postby Morten|Dyalog on Tue Sep 30, 2008 7:16 pm

[Edited to put our current advice at the top on 26 October 2017]

Right click on the shortcut which starts Dyalog and choose "Run as administrator".

Run this user command by typing it into the session and hitting enter:


Please follow the instructions to associate .dws, .dyalog, and .dyapp files with your version.

If you still have problems, please run the following function and contact Dyalog Support.

⎕USING←'' 'System'
checkreg←{⍵=⎕NULL:'No Value'

⎕←'root dwsfile\shell\open\command'
checkreg reg1

⎕←'root Applications\dyalog.exe\shell\open\command'
checkreg reg1

⎕←'HKCU software\Classes\dwsfile\shell\open\command'
checkreg reg1


If you wish to change the program (for example, an older or newer version of Dyalog) used to open .DWS files from the Windows Explorer then you will need to modify the registry.

1) Start regedit
2) Navigate to HKEY_CLASSES_ROOT\dwsfile\shell
3) Edit the values of the "Open\command" and "Open (do not start)\command" keys.

See the following page which illustrates the registry location.

Startup Registry
reg_startup.jpg (47.07 KiB) Viewed 8517 times

Two other extensions associated with Dyalog are ".dyalog" and ".dyappp".

For the ".dyalog" extension edit the section HKEY_CLASSES_ROOT\dyalogfile\shell, and for the ".dyapp" extension, HKEY_CLASSES_ROOT\dyappfile\shell
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Re: How do I control which version is used to open a .DWS file?

Postby Nicolas|Dyalog on Fri Oct 03, 2008 11:59 am

You can also add shell menus by creating new keys :

1) Start regedit
2) Navigate to HKEY_CLASSES_ROOT\dwsfile\shell
3) Create a key with the name you want to appear, for example :
Code: Select all
Open with v9

4) Create a key called
Code: Select all
and set its default value to the command line to execute, for example :
Code: Select all
"C:\Dyalog90\dyalog.exe" "%1"

It should look like :
dwsfile_open_command_registry.jpg (27.18 KiB) Viewed 8495 times

Then when you right click on a .dws file, you should see a new menu :
dwsfile_open_command_shell.jpg (44 KiB) Viewed 8495 times
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