rSync is very efficient way of transferring files between computers, especially over slow WAN connections. rSync can compress data before transferring, but more importantly if there is similar but not identical file with the same name on the target computer it will only transfer differences instead of the whole file.
rSync can be used as a very efficient offsite backup engine as after initial backup is done, subsequent backups can take minutes instead of hours or even days.

There are many Linux and Windows rSync implementations. In this article I will show how to transfer files between two Windows computers using DeltaCopy.

1. Download DeltaCopy on both source and target computers. For more info and latest versions check here.

2. Prepare target computer:
a. Extract .zip file and run DeltaS.exe
b. Click “Register Windows Service”. Select “Use Local Service Account” and click OK
c. Click “Start Server”
d. Change to “Virtual Directories” tab add a new directory (local folder) where your copied files will be saved.

3. Prepare Source Computer:
a. Extract .zip file and run DeltaC.exe
b. Double-click on Add New Profile. Add a new profile using IP address or host name of the target computer you prepared in step 2.
c. In File List tab add files and folders you want to copy.
d. In Options tab you can add additional custom rSync switches. For example -P will keep partially downloaded files (and show transfer progress) so if transfer is interrupted and restarted it will carry on transferring the same file where it finished. Very useful for large files.
e. If required add or modify Schedules to start tasks automatically.

4. To start copying manually on the source computer right click on the Profile Name and click Run Now.

If you added files rather than folders to the copy list you may get an error  in the status window similar to “rsync: change_dir#3 “folder2” (in Backup) failed: No such file or directory (2)“.
Check the first line in the status window. It is the executed rSync command. It will be similar to:
Executing: rsync.exe  -v -rlt -z –chmod=a=rw,Da+x –delete -P “//source/folder1/folder2/myfile.pst” “PC-NAME::Backup/folder2/myfile.pst”
Last part of the command (PC-NAME::Backup/folder2/myfile.pst) shows where files will be saved on rSync server (target computer).
Command fails because folder2 does not exist. Simply create this folder on the target computer in the directory you added in step 2d.
Alternatively add folders rather than files to your copy list.

After copying check file permissions on the target server. rSync may not set correct permissions for copied files. Take ownership if necessary. 

To completely remove DeltaCopy service from Target computer run folowing in command prompt (CMD):
sc delete DeltaCopyService

Tested on:
Windows XP SP3