migration with additional complications

Last year about this time I started developing a web app using WAPP. It
also happened to be my first foray into PostgreSQL.

For various reasons I had to abandon that OS install and
reformat/reinstall WinXP. Time passes... Today I am looking to recover
my work and basically resume where I left off.

One problem is that I never did an "export" of the old database using
pg_dump or similar command. (pg_dump is how you're supposed to do it,
right?) The DB exists in its most evolved form as simply a PostgreSQL
database. I am not sure I will be able to "mount" the old database on
its original PostgreSQL installation -- my backup of files from before I
reformatted is just a "copy", not an "image." I don't think I can turn
it into a bootable "snapshot" of my workstation from 1 year ago.

I could go on about the bastardized techniques I have tried, but rather
than spam up the list with that particular form of comedy entertainment,
I'll just ask: how can I get this data into a new install of PostgreSQL?

Not sure the exact version I was using originally, but it was an 8.3
variant, whatever was the current stable release at the time (was there
a build on 3/17/08? That might be it.). Today I am using 8.3.7-1.

For what it's worth, the application was very much a work in progress,
and I am really more interested in the schemata than the data itself.

Thanks for reading, and for any help!