To fix your new problem with the video drivers, boot to recovery mode and run the following:
It should give you a working video configuration.
sudo dpkg-reconfigure -phigh xserver-xorg
When you have a working video configuration it is a good idea to make a backup of your /etc/X11/xorg.conf file.
When you make Ubuntu the boot drive you should see the 3 Ubuntu kernels plus a non-working Windows option. The grub entry for Windows on this partition is pointing to a Windows on an extended logical drive on the same disk as Ubuntu, which from what you have said is not where it is installed.
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
When you make Mint the boot drive you see the Mint options plus the Ubuntu ones (which work?) and 2 Windows options: Windows NT/2000/XP and Microsoft Windows XP Professional. The Windows NT/2000/XP is pointing to the extended logical drive on the same disk as Ubuntu and so will not work. The Microsoft Windows XP Professional option is pointing to a Windows installation on disk 3, which is where it should be. I'm not sure why this doesn't work.
Is your objective to get to the stage where you don't have to change the drive boot sequence and have all 3 OS on a grub menu?