delete partition on external hard drive

I copied my data files to my external Maxtor hard disk
before I tried to reformat my internal hard drive and
reload Win XP. However during my partition, I didn't
realize I still had the external drive (160GB) plugged in
and it showed up at the top of the list and the original
internal (80GB) below it. So, I followed the instruction
mistakenly and went through the process of deleting the
partition(on the external hard drive) and tried to
partition it into two drives. Then I got an error message
as I continue to try to format the hard drive "Your
computer's startup program cannot gain access to the disk
containing the partition or free free space you choose .
Set up cannot install Window XP on this hard disk." I
stopped, reboot and tried to go through the delete
partition several times with the same error message.
After several attempts, I realized that the external hard
drive was still plugged in. So I unplugged the external
hard drive and reboot to go through the process of
reformatting and partition the internal hard drive into C
drive and E drive and loaded Win XP. Now even though I
plugged in the hard.
After I installed the external hard drive's
software,driver and restarted the computer, I connected
the external hard drive and don't see the drive in my
computer. I could find it under Control
Panel/System/Device Manager/Disk drives but it doesn't
show up as an external hard drive under "My computer" with
a drive letter. Under the disk management, I see the
drive as Disk1 but it was unallocated. Did I lose all my
data due to the delete of partition? Can I recover my
data and drive ?