See this KB page. I think you need to wipe the drive as it seems you have a partition current on the drive. When you get to to the first screen of the Vista install press shift + F10 to get a command prompt then type the following
select disk 0 If you only have one disk on the computer
clean this will delete the drives partition table. using clean all will zero out the drive.
convert mbr you may get an error. If so disregard and continue with the following commands
create partition primary
select partition 1
format fs=ntfs label=(any name you want)
assign letter C:
Then start the install
Sorry, missed Aura's post.
Edited by JohnC_21, 30 June 2015 - 10:09 AM.