Server Won't Start On a Copy of Its Own Data Folder

1. Installed the latest 8.0.3 binary on a Windows XP Pro system as a service to be started on bootup.
2. Used psql just to verify that I can connect.
3. Used Windows Control Panel.Administrative Tools.Services to stop the server cleanly.
4. Made a copy of the PostgreSQL/8.0/data folder
5. Renamed the installed folder as PostgreSQL/8.0/saved-data
6. Renamed the copy of data as PostrgeSQL/8.0/data
7. Used Windows Control Panel.Administrative Tools.Services to start the server
8. The server fails to come up

Windows comes back and tells me that the service started and stopped. The Windows
EventLog show that the postgres server was sent a start control, entered the running state and
then entered the stopped state. There was nothing new in the pg_log folder to provide
any clue.

I renamed the saved-data folder back to data and used the Services tool to start the server
with success but further attemps to start it with a copy of the data folder all fail in the same way.

Based on what I've gleaned on reading some of the past mail archives, I thought that this should
work. Have I misunderstood something?

I went through this exercise in trying to solve a problem I posted about on Monday
([ADMIN] Trouble Getting Database Server Started) trying to recover a database on
a computer that may have powered down when the server was running. I don't know
what happened but I can't start the server any more on that computer. My goal is to
install the data folder from that computer on a new install of postgres on a second
computer.

Thanks for any help anyone can offer,
Dirk Kalp