Ok, I figured it out, and how I figured it out is pretty funny. I had basically resigned myself to having to reinstall Windows, so I went to make an Acronis backup of my OS drive because I do have some data on there I need.

My machine has a total of five hard drives in it, and only the OS drive is solid state. When I tried to back it up to one of my Seagate 1.5TB storage drives Acronis starting throwing write errors. As many of the posts here reference hard drive failure as a cause of the aswrvtsys hang, I went into the BIOS, disabled the controller the two big Seagate drives run on, and voila! - the system booted and completed the system restore I had attempted about a week ago, lol.

I just ran Windows Updates and rebooted, and everything appears to be working just fine. Now I just need to RMA this drive.

I really appreciate your help!