initdb crash after install

Greetings.

I have read many of the questions concerning this issue. I
too have installed PostgreSQL 6.5.3 faithfully following the
instructions in the INSTALL file. The initdb crashes with
the following error:

ERROR:  pg_atoi: error in "template1": can't parse
"template1"

In my reading of the question archive, I see the solution
seems to be to clean out all the old templates. We did a
fresh install of Redhat 6.2 in a CS class, and it must
automatically install postgres because postgres was already
present on the system.

My question is:  How does one find all the old libraries and
clean them out?

Thanks for your time,

Jim Buckley,
CS Student,
Oregon State University.