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A while ago, I added a number of context menu commands to import Kindle books into Calibre and convert them to EPUB (under HKEY_CLASSES_ROOT\Amazon.Kindle.content). All associated extensions are set in the registry to point at Amazon.Kindle.content. This has been working great up until today, when the commands stopped showing up for .mobi files. When I right click a .azl, .azs, .azw, .azw3, .azw4, .prc or .tpz file, they appear and work as expected. But not for .mobi. Here are my registry entries for .azw and .mobi — they look exactly the same to me so I have no idea what is going on:



jscholes@rebus:~$ cat >azw.reg
Windows Registry Editor Version 5.00


jscholes@rebus:~$ cat >mobi.reg
Windows Registry Editor Version 5.00


jscholes@rebus:~$ diff azw.reg mobi.reg
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Have you tried deleting and re-creating the keys for mobi? Did you install anything recently that might have associated itself with the extension? – Karan Apr 25 '13 at 15:45
Yes. So far, I've tried: Deleting and recreating HKEY_CLASSES_ROOT\.mobi; doing the same for other Kindle-related file extensions; removing and restoring my additional commands in HKEY_CLASSES_ROOT\Amazon.Kindle.content; and reinstalling Kindle for PC (which creates the file associations in the first place). In Windows Explorer, when focussed on a .mobi file the Type column shows "MOBI File." When focussed on a file with any of the (working) extensions it shows "Amazon Content." I don't understand why .mobi files aren't being appropriately associated. – James Scholes Apr 25 '13 at 15:52
See my own answer. I don't really understand why that solution worked, but glad the problem is fixed. – James Scholes Apr 25 '13 at 15:58
up vote 0 down vote accepted

The solution, which I probably should've tried sooner, was to set the default program for .mobi files to Kindle for PC. Nothing has been altered in after doing this, but the commands now show when right-clicking a .mobi file.

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