It does work. (Windows XP or 7) I’m on Windows 7 64 bit Cubase 64 bit.
If you need help, there are several here who would help you. I use 4 screens (I must be really pro 
) and in the past have used them just like Rhino describes. Now I have switched so 2 screens are on “full mixer” mode and the Cubase “shell” is stretched over the other 2 screens. Link the mixers and the project page. Of the other 2 screens one is dedicated to the project and the other is split in half. The lower half is Mixer 3 that contains In’s Out’s Groups’ effect channels, and master out. The upper half I keep “blank” for opening and closing VST’s VSTI’s and editing midi/audio. The main thing is…it works for the way I work…up to the point where IMO the glaring issues are key commands, focus, and navigation issues, most of them in the mix console…the WORKFLOW things!
I suggest anyone new to multiple screens try them out like Rhino has described in prior posts at gearslutz, and then deviate from there if needed. Remember the options of AOT! Obviously everyone works differently, but based on the many complaints about this topic over the years, I have discovered what he does is not perfect, but often the most effective.
Actually I have noticed most commercial studios including some very well known ME’s using Wavelab keep things down to 1 screen.
Anyway if you need assistance, give is your specific issue. I have been using multiple screens with Cubase for at least the past 14 years and unless you have some specific problem this is not rocket science.