Win 8.1"Cache_Manager" error after Bootcamp drivers install

I've googled and searched this forum for help to no avail other than something somewhat Hackintosh related on Tomshardware dot com. I have very limited post-Windows XP knowledge, so here's my problem:

I've installed Windows 8.1 64 bit on a MP 5,1 12-core running 10.10.3. with 64GB of RAM and a flashed/modded ATI 7990. The install went flawlessly and surprisingly quickly. I then installed the latest Bootcamp drivers off of my flash drive. When I rebooted the computer and I got a BSOD immediately after I signed in with a message related to a problem with the "Cache_Manager". I then "Reset" Windows 8.1 using the install DVD which allowed me to remove all 3rd party programs without doing a complete system reinstall. I then started to load one Bootcamp driver at a time. I have loaded just the Reltek soundcard driver from the Bootcamp list of drivers, but chose to load the CPU driver I got direct from AMD.

So far, all is well, but I'm just getting started. I have no problem loading one driver at a time, if necessary, in an effort to circumvent the "Cache_Manager" issue. So the question I have is this: Do I need to load any additional Bootcamp drivers for Windows 8.1 to run optimally? All I need is sound and GPU (which I have) and possibly a USB3 card down the road. I don't need bluetooth or wireless network support. I'm using a Logitec USB mouse and Windows 8.1 even recognizes my old G3 iMac keyboard and supports its audio adjustment buttons if you can believe that!

TIA!

JP