How to recover a postgres installation from files

Hello.

I have a not bootable Windows Server with Postgres 8.1, now I am trying to
recover it but as I can't boot the windows, I can't  start the postgres
service and I can't do a "Backup"
So, I only have the postgres directory on my hands. I decide to install the
same database version in another computer and replace DATA directory, but I
notice that 8.1 (windows binary) is not available for download.

So, I don't know how to recover the database from the data directory of a
windows postgres 8.1 installation.

Can you help me?