1. Boot using live CD/DVD/USB
If you cannot get to desktop, run commands
sudo Xorg -configure
sudo cp /mint/home/xorg.conf.new /etc/X11/xorg.conf
starx
If you still cannot get to desktop, run command
startx failsafe
Now you should boot to the white terminal, from where you can install Mint
2. Remove ubuquity-slideshow-mint package
sudo apt-get remove ubuquity-slideshow-mint
3. Install Mint
sudo ubiquity
On the box where you set username, password and computer name, you have to move using keyboard. Next and back buttons work on mouse.
4. Drink some coffee and keep your fingers crossed ..
Tested on Mint 12. In the default session has problems with menu and bars, but gnome session works fine ..

