If you don't care about the previous data, just boot into rescue mode, and
use fdisk to write a clean empty partition table to the disk, then reboot
into installation mode.  That's cleared up some issues for me in the past.

Dan W.

> > >        Error informing the kernel about modifications to 
> > >        partition/dev/sda5--Device or resource busy. This means Linux 
> > >        won't know about any changes you made to /dev/sda5 until you 
> > >        reboot--so you shouldn't mount it or use it in any way before 
> > >        rebooting.