istall of 9.1 remix

[Gary Kirkpatrick]

Friend wants ubuntu on her Eee 10" notebook.  When the partitioner
   loads it reveals on sda1 there is windows 7 loader on 100g partition.
   Sda2 has 122.9g.  Sda3 has 10gig and vista loader, sda 4 just had 15.7
   meg of space.
   Friend wants to keep windows 7 but not vista.  I know how to wipe the
   10 gig space ande format it to ext 3 and tell it to use /home but I
   can not see how to make sure 9.1 installs to the 10 gig space.  Also
   after wiping the 10 gig space and setting it to /home, I click forward
   and I get an error message saying their is no root partition and it
   tells me to use the menu to set one up.  But I can not see how to do
   that.
   Thanks for any  help
   gary