Hi everyone

I've decided to try Ubuntu 12.4 32 bit lts after my Windows 7 desktop computer gave me so many headaches.
I have installed ubuntu alongside a reformatted version of windows 7. After reboot, i managed to enter my personal details and machine name etc and rebooted again. Now when i try to boot, i can select what operating system to chose from then the screen turns purple and then black but nothing happens afterwards,

could it be that i use to use windows 64 bit and now im using ubuntu 32 bit? Im not really a tech expert so please advise in laymans terms thanks.