I have almost the identical situation but with Windows 10 - 64 bit, and LOTRO. AMD Radeon 7800 2GB DDR5, 4 - Intel(R) Core(TM) i7- 4770 3.4 GHz, 8GB DDR3(1333) ASROCK H81M-HDS and my frame rates dropped to 6 fps after updating all drivers for mobo and GPU. Everything ran fine until January time frame. I thought it might be Windows updates so I installed another disk with 8.1 -64bit. Downloaded all the latest drivers for everything. Same thing. I even turned off every background programs in both 10 and 8.1. Contacted Turbine and they could not help. I max at about 20 fps if I turn off all the graphics that make the game worth while and I still cannot play. The GPU driver update is the common factor. I have tried everything but switching the GPU. The Computer originally came with 8.1 and and even ran with windows 10 until the GPU driver updates. I have the very latest AMD drivers right now. Several have recently come out. I keep hoping AMD will fix the problem. Others in the game are experiencing similar problems. I plan to poll them and see who is running AMD GPU's. I payed to play the game but cannot.