How can I let another PC using Windows XP (Service Pack3) read Mac OS Extended (Journaled) volumes? Windows XP shows nothing.
Boot Camp Drivers
You can use the Boot Camp drivers which integrates HFS read/write into Explorer.
You don't need Boot Camp to download/install the drivers.
Alternatively, you can use HFSExplorer:
HFSExplorer is an application that can read Mac-formatted hard disks and disk images. It can read the file systems HFS (Mac OS Standard), HFS+ (Mac OS Extended) and HFSX (Mac OS Extended with case sensitive file names).
If you are connecting to the Mac over the network, you need to make sure SMB sharing is turned on.
First in System Preferences open Sharing
Then check File Sharing and match folders that you want shared and with whom
I allow both SMB and AFP. The SMB handles the translation for Windows.
These are the exact settings I use and I work and move files over Windows, OS X, and Linux.