Kali Linux 32 Bit System Installation Fail.

can anybody help me.i am trying to install kali linux for like 5 days now....fail....fail...fail... thats all im getting. im installing kali linux 32 bit on oracle virtual box.when i try to install it everything goes fine untill wen its installing the system it loads all tha way to 80% then it just says system installation fail then when i retry it dosent eaven load 1 %. did i set up th virtual machine wrong? my computer is a recently formated windows xp to windows 7 home premium . it had only like .5 gb of ram but i added 1gb so it has 1.5 gb of ram. what do i do to install it..please if u can step by step (y) or video. i was following the steps off this video >>>> https://www.youtube.com/watch?v=Rka5MqnCn1E <<<<<