After about a year or so of normal use Photo Gallery developed an annoying bug:  The vast majority of my thumbnails show up as the generic mountain icon!  If I double click on one, the picture displays normally.  Windows explorer shows thumbnails for the same pictures folder just fine.

Things that I have tried in order to fix this:

1) Going to control panel>folder options>view and making sure that "Always show icons, never thumbnails" is unchecked

2) Renaming/deleting the Pictures.pd6 in AppData>Local>Microsoft>Windows Live Photo Gallery

3) Deleting entirely the Windows Live and Windows Live Photo Gallery folders in AppData

4) Uninstalling and re-installing

5) Uninstalling and re-installing a previous version (2011)

6) Running command prompt>sfc/scannow (It showed no problems)

7) Deleting the windows thumbnail database via disk cleanup

8) Running the Microsoft Fix it for Photo Gallery at http://support.microsoft.com/mats/windows_photo_and_slideshow_diag/?wa=wsignin1.0

 

My computer has an SSD on C:\ and a HDD on D:\.  I should add that I set my user directory to a non-default location via a registry edit, so my user directory is D:\Alex.  I highly doubt this is the cause since Photo Gallery was working fine for about a year.  When I boot up on my HDD side and run Photo Gallery, it works normally.