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I am on windows server 2003, but I guess it is the same on windows xp.

I moved some movable applications (usually people create them for usb sticks) to locations like c:\bin\app1\app1.exe. The old location was c:\programs\app1\app1.exe

app1.exe can open files of type *.ap1

When I rightclick file.ap1 and choose open with ... the Open with dialog appears. But it is not working how I expect in this situation. I can choose c:\bin\app1\app1.exe with the "Browse" button, but:

  • app1.exe will not appear in the dialog where I just choosed it in the programs list, like I am used to it after clicking OK on it in the browse dialog.

  • app1.exe will not open it when I click ok in the "Open with" dialog, the application that was assigned until then will still open it

What could be the reason?

  • my account is member of the administrators group
  • I just changed the permissions of the folder c:\bin\app1\ and made sure that the group "Administrators" has all rights. I also inherited this manually to all subfodlers and subfiles.
  • I also tried to move the application (with the whole folder) to "c:\program files\app1\app1.exe
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up vote 1 down vote accepted

This is only a workaround, so if anyone finds a better answer, I will gladly accept it.

I removed all old references to app1.exe by searching the registry for "app1".

The registry references app1 by different names like "Application One", I searched and removed all of them.

I restarted windows (don't know if this is necessary)

After the restart I could do what I wanted to do (with app1.exe)

Still feels like a dirty hack.

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this is more like uninstall and reinstall in different location :) – Remus Rigo May 16 '10 at 20:26

The windows registry keeps track of file types and the applications used to handle them. The overall concept is "file association".

The file type *.txt will be "associated" with one or more applications that can handle this file type. For each file type there is a range of actions that can be performed on the file, known as "verbs". For example: open, print, edit.

For a practical example locate the following registry keys and check the content:

Go to HKEY_CLASSES_ROOT\.txt and check the value of "(Standard)" or "". In my case it says txtfile. Now go to HKEY_CLASSES_ROOT\txtfile and see what content is here. Notice under HKEY_CLASSES_ROOT\txtfile\shell there are a bunch of "verbs" or actions defined, one of which is the "open" key. The sub key "command" will specify a command line to run when any *.txt file is double clicked in explorer. In my case this is:

"%SystemRoot%\System32\NOTEPAD.EXE %1"

The %1 in this command line will expand to the full path of the file you double clicked. Hence double clicking a *.txt file will run Notepad.exe with the full path to the double clicked file as command line.

By locating the corresponding registry sections relating to *.ap1 you should be able to change the command line to point to the right path for the executable.

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