Man, what a pain in the ass this was to debug. The image file previews weren't showing up at all, no matter what the settings were.
(Note that this is a guide for fixing image thumbnails, not videos)
Well, they sorta did. The image/picture thumbnail would flicker and appear then disappear, showing only the file icon instead.
I've tried all of the following:
- Changing the settings in Windows Explorer > Folder View options
- Changing the settings in Local Group Policy Editor (gpedit.msc) > User Configuration > Administrative Templates > Windows Components > Windows Explorer
- Changing the settings in Advanced System Settings > Performance
- Rebuilding of icon cache (requires reboot)
- Using Disk Cleanup to delete thumbnail cache.
- Checking the registry values for the file types.
*update 6/6/2013* Some additional tips from readers are:
- Clear your recycle bin
- Right click on Computer > Properties > Advanced System Settings > Performance > Settings > "Let Windows choose what's best for my computer" > OK
None of them worked. And I am unwilling to:
- Format the drive (due to the time it'd take to reinstall and configure everything!)
- Install a codec pack as an alternate method of rendering thumbnails (extra bloat)
But then I found a solution by accident... without having to format. Here's a clue.
Yep. That's right! If you're low on disk space then it wont generate thumbnails for you.
I moved some big files off my desktop onto another drive and the thumbnails immediately started working again!
I think the minimum space you need on your Windows drive is 500mb. I could be wrong, but after moving the files everything was fine again.
*update 21/6/2012* Adding link to previous post: Windows: Regain disk space on C drive with some uncommon methods
These sources didn't work for me, but in the case clearing up disk space didn't work for you, here were some of the more useful links I found.