i tried partitioning my hard disk yesterday, so that i could install a second os.
however when it rebooted it said 'windows failed to start'
it then gave me two options 'launch start up repair' or 'start windows normally'
'launch start up repair' just brought up the same screen and 'start windows normally' booted the black loading screen right at the start but it crashed even before the bar got half way across.
when i attempted to reinstall vista it gave me three places to install the OS
recovery - not enough space
unallocated space - the partition i tried to create (230 ish gig)
and my second hard disk - cant install on the for some reason, even after formatting

any ideas on what i can do to fix this?

Hi and welcome to PCHF

It looks like your partitioning didn't work correctly. Try re sizing or re creating the partition with FDISK (How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk) or another partitioning tool such as Partition Manager, if you can boot into Windows.

are you sure fdisk will work even though vista lacks dos?

Check this out...Windows Vista Help: Can I repartition my hard disk?

i cant boot in to windows

Absolutely, if you use a bootdisk.