Thanks for all the help!
I think I'm just going to have to reinstall windows. I've managed to manually hack some of my icons back to normal, but there are some that are still a mess. The 'composite' folder icons showing thumbnails of the folder contents look like an absolute mess, which is a shame.
In response to...
...Reply #1: I got IconPackager 5 as part of the ObjectDesktop bundle, and I didn't see the IconPackager store page. (See below...)
...Reply #2: I did try that several times, with a reboot each time, with no luck. Thanks for the suggestion, though!
...Reply #4: Yeah. I tried to do a System Restore, but for some unknown reason all the system restore points prior to the installation of IconPackager have disappeared. I don't know how, but they're just gone. (Also, I'm not a 'he', I'm a 'she'.)
...Reply #5: I did find this tip offered on another site to cute the problem, but it didn't seem to help. Thanks for that suggestion too!
...Reply #6: I actually have a support ticket pending with Stardock. No reply as of yet, though.
...Reply #7: I tried clearing the icon cache after rebooting into safe command prompt mode (so explorer.exe wasn't running and couldn't get in the way) but that didn't help. Thanks for that suggestion too!
So, in a nutshell, before I bought the ObjectDesktop bundle, I had a look through the compatibility matrix on the store page (shown at https://www.stardock.com/products/odnt/images/odnt_compatibilitymatrix_10.26.15.png ). That matrix listed "Start10" as being the only app *not* compatible with Windows 8. So I made a mental note that *everything* in the bundle would be cool *except* Start10. "Everything is good to try *except* Start10," I said to myself.
It never occurred to me that I would be given access to an application that was not listed in that matrix. If I'd known that IconPackager was in the ObjectDesktop bundle, but not listed in that matrix, I would have checked its system compatibility independently. So, it's a bit of a mess.
To be honest, I'm a little baffled as to why IconPackager would do *anything* if it is run on an operating system it does not recognise. Surely, an application like IconPackager that does a *lot* of hectic work "under the hood" would check the environment it's running in before it starts hacking away at stuff? I mean, there are system calls that programmers can use to check that, right? Plus, shouldn't the software look at what it's changing before it changes it? Look before you leap, right?
StarDock make some awesome software, but wow... IconPackager has really boggled my mind.