Got a status report-

It turned out that it wasn't a hard drive giving me trouble but rather a problematic Poser item I had installed in my Runtimes.  More specifically, something called "V4WetCreator" is the item in question- it's a texture package that uses Python code to initialize changes to textures.  This would be fine, except for that what it actually does is go through and delete all files and folders in your Poser Runtime until you're left with the "Fatal Runtime Error" pop-up.  

And I know it's the problem because I got curious and tried it again after reinstalling Poser.  

So please- be very weary of "V4WetCreator".