Problems with "File Association" in Windows 7 64-bit

Xandragnis, you have just saved my day! :) In fact I moved the application from one drive to an other and the parth there has not followed.

This seemed like the answer, since the suggestions in the succeeding response from Syed at MS didn't resolve my issue.  Unfortunately, I did the Regedit thing for Acrobat 9, the one probram I'm now trying to set as  default, but "Change Program" in "Set Defaults" still will not accept (or recognize) any programs in the "Program Files (x86)" folder - only those in "Program Files".  There's gotta be a straightforward way to fix this - short of reloading the whole operating system.  I suppose the answer might be further down this thread - or in another forum - but this looked like such a logical solution that I hoped it would work.:-(

This seemed like the answer, since the suggestions in the succeeding response from Syed at MS didn't resolve my issue.  Unfortunately, I did the Regedit thing for Acrobat 9, the one probram I'm now trying to set as  default, but "Change Program" in "Set Defaults" still will not accept (or recognize) any programs in the "Program Files (x86)" folder - only those in "Program Files".  There's gotta be a straightforward way to fix this - short of reloading the whole operating system.  I suppose the answer might be further down this thread - or in another forum - but this looked like such a logical solution that I hoped it would work.:-(

What did work for me was the following:

STEP 1 - CHECK LOCATION OF THE EXECUTABLE FILE

Check to make sure that Windows knows where the executable file can be found, other wise the file will not open with the correct program when you double click it. You have to use "regedit" fo perform the following fixes

Navigate to:

HKEY_CLASSES_ROOT\Applications and and find your .exe name.

Expand the tree to shell>open>command.

In the Default change its location to the actual location of the executable, hit OK and then try and re-associate the file type as you normally would.

If this does not correct the issue go to Step 2

STEP 2 - CHECK FILE ASSOCIATIONS

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts

Scroll down to your file extent, for example, ".txt" and expand the tree, and select the “OpenWithList” tab. Here you will see one or more programs that Windows thinks your file opens with. 

The MRUList gives Windows the order in which the programs will be seeked out to open your file. Look carefully and you may see that there may be more than one selection. In the case of my files, Wordpad was there as well as Notepad but selection “a” was Wordpad and selection “b” was Notepad. 

My MRUList was set to “ab” making Wordpad open the ".txt" file instead of Notepad so I changed the MRUList order to "ba" and now when I double click on any "txt" fle it is opened by Notepad

After playing around a lil I think I've figured it out.. [for me at least..]

The program that you're pointing to isn't registered correctly.

In regedit: Navigate to Computer\HKEY_CLASSES_ROOT\Applicationsand find your .exe name.

Navigate under its name to shell>open>command. In the Default change its location to the actual location of the executable, hit okay and then try and reassociate the file type as you normally would.

Let me know if that doesn't seem to work.

This method works for my case due to same program different version installed with different path.

Thanks to found this after few days searching.