See Link below:
http://www.sevenforums.com/tutorials/2668-partition-volume-delete.html
OPTION ONE: Easiest to use, and because you have separate hard drives, after completing OPTION ONE; all you have to do is start back at number one and make you XP Drive Active. that way you have a Backup...
Try this:
http://blogs.technet.com/b/ouc1too/archive/2013/10/25/something-happened-in-the-install-of-windows-8-1-can-t-be-completed-and-now-you-re-annoyed.aspx
other ideas that worked for me: download 8.1 iso.
if you need help or additional info, please reply
download Active KillDisk FREE Suite and install. listed in the program listing (start Menu, all Programs) you will find a folder called Bootable Disk Creators expand to find two options:
Bootable DOS CD Disk Creator and
Bootable DOS Floppy or USB Disk Creator.
I prefer Bootable DOS CD Disk...