Windows – ny way to play GIFs with Windows Photo Viewer

In fact, it is a bug in 7-Zip. As program's author Igor Pavlov explains, the following happens when Windows Photo Viewer is set as default image viewer in Windows:

The Program1 (some photo file handler) calls another Program2 (windows photo viewer) and closes Program1. But 7-Zip waits only Program1. So it deletes image from temp folder. I plan to fix that problem in future.

The problem still exists in latest stable 7-Zip 9.20, though I didn't check if it is fixed in latest alpha.

There is a not-so-difficult workaround: use alternative image viewer as your default one. Personally, I use FastStone, but XnView etc. should be fine too.

To open a picture with the Windows Photo Viewer, the following command is used:

rundll32.exe C:\WINDOWS\System32\shimgvw.dll,ImageView_Fullscreen "%1"

where %1 is the picture you want to open, so if you want your picture to open you need to adjust

HKEY_CLASSES_ROOT\giffile\shell\Open\Command\(Default)

to the above command and remove any other subkeys.

As this is not an executable and you seem to have somehow removed the open with entry which must be at

HKEY_CLASSES_ROOT\.gif\OpenWithList\*

or somewhere else I'm yet unaware of for the Windows Photo Viewer to not appear for you.