Picasa broke SageThumbs image thumbnails

A week or so back, I installed Picasa, but when I did, it broke SageThumbs and removed the "edit with Gimp" context menu (I was able to work around this via Default Program Editor; It didn't legitimately fix the problem, though). Now any images display the default image icon instead of preview thumbnail.

I uninstalled Picasa, but that didn't work. Then I uninstalled and re-installed both Gimp and SageThumbs, but neither the thumbnails are displaying, nor the "edit with Gimp" context menu (which I have worked around).

Any help would be much appreciated. I tried looking around the internet, but I didn't come up with much, and I'm not what you would consider to be "computer savvy." Thanks.

Run CCleaner, tools, startup, context menu - see if edit with Gimp is listed, enable if possible.

See if this helps with thumbnails - Thumbnail Previews - Enable or Disable

I don't think that worked. Is there a setting of some sort that Picasa changed when it was installed, or possibly a remaining file from it that prohibits SageThumbs from functioning?
Also, "edit with Gimp," was not listed.

See if this helps with Edit with Gimp contect menu - "Edit With Gimp" Context Menu Missing

I will search for SageThumbs

Edit: See How to fix missing thumbnail previews for image files in Windows - freewaregenius.com for thumbnails (3rd option is SageThumbs though, so try the first 2, then again you already tried 1? Still do them both again in case)

Edit 2: From SageThump website (not sure if this will help at all)

Troubleshooting
To fix unwanted SageThumbs extension:
1. Uncheck problem extension in SageThumbs options and
press OK;
2. Restore extension association in original application
or using Windows Control Panel;
3. Clear Windows thumbnail cache using Windows Clean
Manager (cleanmgr.exe);
4. Reboot.
Note: It may be sufficient to make not all those steps.

Did you check these options?