Boot the machine from your CD#1, set 'rescue' mode, then run fdisk at the prompt an re-create partitions EXACTLY as it was before. If you are able to re-create EXACTLY the same partition table, and NO MORE info was destroyed from the hd, then you can "Mandy" again immediately.
If the partition table was created by an installation wizard it can be easy to re-create it redoing the installation up to a certain point. That could be achieved stopping the installation process after the partition table creation. Obviously you must tell the wizard EXACTLY the same partitions, types, sizes.... DON'T ALLOW to give format to partitions !!!! ... if there is an option for not give format to partitions, check it. Don't attempt if not sure how to avoid the formatting step !!!! (that will destroy your data).
Then three-fingers after the partitioning step and......
Good Luck !
(absolutely no-guaranteed process)