First, what video card do you have in the system ie. GT9600? 2nd have you put in the right HorizSync & VertRefresh in your /etc/X11/xorg.conf file? Most times you don't need to worry about it, but sometimes you need to edit the file and manualy enter the right settings. If you have the above mentioned Nvidia card I believe you will need the 173. driver. If your repository does not offer it you can go to nividia.com and download the needed driver.

I see you mention Win8 does your monitor have touch screen? If so it could be that linuxmint does not support a touch screen.