Always one.... or in this case, zero...
I've installed Sophos Anti Virus far too many times to be able to count using fingers, toes, limbs, appendages and hair follicles. And it's worked perfectly every time. So, on this one occasion that I'm reinstalling XP on an existing box (from scratch, with full format), it decided to show this:
Still installed absolutely fine though
So in terms of packages, you were undefined% of the way done?