Newbie Instal Problem

hi all,

i'm new to pgsql, although i've developed several databases using
access and vb / access.  anyway, i want to ditch that approach and go
open source with php and postgresql.

i'm using wrox's beginning databases with postgresql as my guide and
i've run into a problem.  i don't want to install cygwin with a pgsql
database as part of the package b/c i want 7.4.3, not 7.4.1.  i tried
to work within the book's instructions, but couldn't get it to work.
i also checked the newsgroups and the net.

i have cygwin installed just fine (the distribution without pgsql
database).

i downloaded postgresql-7.4.3.tar.gz fine.  i put it into
cygwin/usr/src.

i open cygwin and type "tar zxvf postgresql-7.4.3.tar.gz" at the
opening $ prompt and get a no such file or folder error.  i think it
is a directory issue, but it isn't addressed in the book.

any help would be appreciated.

tia...