what is the cpu. press f2 f4 f11 and f12 and see the blue bios page... and it iwll say n455 or n20 or somehting. 270 is 32 bit, and 450 is 64 bit...
just go to ubuntu.com and download 64 bit ubuntu free, put it on flash drive, and if itboots, its 64 if it error, its 32