New computer with Windows 7 installed, I defrag, shrink, re-boot from Ubuntu LiveUSB, go to gparted and look at partitions before installing Ubuntu....for some reason Win7 is still taking up 400G of my HD!

I resized partition down with gparted, exit and yes of course I can't boot into Windows.

When I go to install Ubuntu in new large unallocated space I get a blank screen at the point you are asked what kind of installation you want.

I have Ubuntu 12.04 LiveUSB, Windows 7 re-installation disk and driver disks also. The HDD currently has 3 allocated partitions: 'diag' fat16, 'recovery' ntfs and 'OS' ntfs which has a red '!' next to it.