I have a Windows 7 Ult. x64 PC with an XFX Radeon R9 200 series video card with 2 LCD monitors connected via DVI. I have a 55" 4K TV (Toshiba 55L621U) which I'd like to connect via HDMI (certified) cable. When I try to adjust desktop settings by either extending my desktop to the 3rd monitor (i.e. TV) or duplicating my desktop onto the 2nd monitor plus the TV, both fail with the "can't save settings" error.