Moving postgresql data to another computer

Good Day All,

I am a newbie to PostgreSQL and I recently installed it on my desktop
(Windows XP). I am traveling now (laptop is Windows Vista) and I needed
access to my database. So before I left, I installed PosgreSQL on the
laptop and then copied the data in the PostgreSQL data directory over to my
laptop.

I put the data directory from my desktop in a different place on my laptop
and now I would like to access the data. I naively tried to just replace
all the files in the data directory on my laptop with the files from the
data directory of the desktop.

When I do that I get the following error: "could not connect to server:
Connection refused (0x0000274D/10061) Is the server running on host
"127.0.0.1" and accepting TCP/IP connections on port 5432? "

I've tried searching the archives and the FAQs but to no avail. Could
someone point me in the correct direction to move this data to another
computer ?

Thanks in advance