Help regards lost boot disc label

Is there any one who can help with a cats server failure? A power cut 
killed it

It refuses to boot saying No disklabel  Input/output error.

I have the info on the original disclabel but how can this help me 
restore the disc if it
is salvageable.

If I have to reinstall netBSD I would use 1.6.1 which I have an iso 
image of.
I looked inside the iso image and all contents of the sets are .tgz.
Is this all sorted out on installation?
I am new to BSD being a unix/linux type as yet.

Regards
mike