FWIW: Every attempt made to install Windows...should result in a new boot entry. Every partially successful attempt to install where there is an existing install...may result in duplicate Windows folders.
I agree that the simplest solution would be to just delete all existing partitions...format/install again.
But it's not the only way to correct this.
You could boot into the install which you want to keep...and do two things:
a. Delete all other Windows folders, taking care that you choose the right ones.
b. Modify the boot.ini file via Removing the invalid entries from Boot.ini - http://windowsxp.mvps.org/bootopt.htm
. There are other ways to do this but they are more laborious, IMO.