Ubuntu linux installiation help problems with virtual disk?

[James F]

Im trying to install ubuntu linux 8.04 on my pc, im running win xp and i have the live cd versio of ubuntu, i've run it off the cd before and there were no probs but im trying to intall it alongsides windows and in the ubuntu setup installation it says creating virtual disks and it does that for ages and never acctually does it, ive defraged my HDD with jkdefrag some plz help me

also im installing in on a external HDD it shouldnt have anything to do with it i just thought i'd mension it