I have been working with Windows 8 and a single monitor for months now, I bought a second monitor today and it doesn't seem to want to work.
So the first main monitor I have is a Dell u2711 27-inch, the second which I bought today is a Dell 24" U2412M Widescreen.
When I plug in the second monitor, I get booted to the Windows 8 login or 'welcome' screen. I am asked for my password. While on this screen I can quite happily move my mouse over to the next monitor and all appears to be fine. But I pop in the password, press enter and then i'm booted back to the login screen.
The second monitor flashes blue after hitting enter.
My graphics card is: Gigabyte GTX 760 OC Windforce 2GB.
Something to note is that my 27" monitor uses a dual DVI link connection, whilst the secondary 24" uses a normal DVI connection. I thought it was something to do with this at first but I'm not entirely sure now.
Ah yes, I considered that too, very strange though considering there's very few issues with dual monitors for other people. Thanks for the help, going to try these two monitors connected to a friend's PC as well.
I just installed a 4th screen above my 3x eyefinity setup and had similar issues with 8.1. My gfx cards are AMD so its probably an OS glitch rather than your nvidia drivers. I couldn't get past the user log in screen, I'd enter my PW and all 4 would just go black. I don't really have much advice for a solution, I attempted to log in several times and then would hard reset. All 4 eventually made it to the desktop/metro after the 4th or 5th hard reset.
8.1 has been really glitchy for me. The mouse issues are driving me nuts.
I know this says solved already but I just had this problem yesterday. After checking connections, updating drivers and looking online for an answer, I finally broke down and called tech support. After a few hours we figured out that Windows 8.1 was not supporting the analog cable I had the second monitor hooked up with. If you are struggling with this like I was, save yourself a couple hours and try a direct DVI connection. Between that and updated drivers it's working just fine now.