How to Synchronize Your Files Between Two Computers Using a USB Drive

A USB drive large enough to contain the pictures, documents and other files you would like synchronized.

Download the fsync.exe utility from http://www.vicobiscotti.it - A great utility for copying only files that have been updated. Direct link: http://www.vicobiscotti.it/fsync_1_4.zip for version 1.4- the latest as of this writing.

Download the dels.exe utility from http://www.gammadyne.com/ - a great utility for cleaning up unwanted files. Direct link: http://www.gammadyne.com/dels.exe

Preparation:

Plug the USB drive into an empty USB slot and note the drive letter assigned to it. For my examples, this will be the F: drive.
Format the USB drive so that it is completely empty and free from errors.
Unzip fsync_1_4.zip so that all files are in the root directory on the USB drive.
Copy the dels.exe to the root directory on the USB drive.
Create a directory under your "My Documents" directory using a conveniently short name, perhaps your initials. For our purposes this will be "abc", but feel free to use whatever you like. Create this same directory on the USB drive. The actual location of this directory will be "C:\Documents and Settings\[Your login name]\My Documents\abc" (C:\Users\[Your Login Name]\My Documents for those using Vista). The actual name of the directory doesn't matter since we will be using the environment variable supplied by Windows: %HOMEDRIVE&%HOMEPATH%\My Documents\abc, but it is important for the USB drive to consistently mount to a specific drive, like F:.
Create a .bat file named sync.bat on the root directory of your F: drive. It should like similar to this:

@echo off
echo Starting Synchonization...
echo Cleaning up...
f:\dels.exe "%HOMEDRIVE%%HOMEPATH%\My Documents\abc\Thumbs.db"
echo ""
echo Synchonizing %HOMEDRIVE%%HOMEPATH%\My Documents\abc to F:\abc
f:\fsync.exe "%HOMEDRIVE%%HOMEPATH%\My Documents\abc" "f:\abc" /D /C /AC /L
pause

Create another .bat file named syncback.bat that looks like this:

@echo off
echo Starting Synchonization...
echo Synchonizing F:\abc to %HOMEDRIVE%%HOMEPATH%\My Documents\abc
f:\fsync.exe "f:\abc" "%HOMEDRIVE%%HOMEPATH%\My Documents\abc" /D /C /AC /L /EThumbs.db
pause

These files will control how your synchronizations work.

Details:

Each batch file first deletes stale Thumbs.db files lying around in directories. There is no need to copy these files as they are generated dynamically by Windows. The next step is synchronizing the files. Sync.bat copies files to the USB Drive while Syncback.bat copies files back to the computer. The options I've passed to fsync control how the files will be copied. Just run f:\fsync.exe to get help for this command. In sync.bat we use /D to log file copying to the console. /C uses conservative mode (doesn't delete files that are missing). /AC disables attribute checking, which will slow down the process. /L logs the operations to a file - useful if anything goes wrong. Syncback.bat works much the same way except we add /E so that Thumbs.db files are ignored.

The process:

At the end of the day or whenever you are done working on a particular computer, insert the USB Drive into a convenient USB port (verify the drive letter assigned is correct) then run the .bat file sync.bat. Before you start working on another computer use the insert the USB Drive into that computer and run the syncback.bat file. This should keep your files organized and updated on both computers.

Notes:

Beware of running low on disk space on the USB Drive. Only sync the files you absolutely need on both computers by cleaning out your sync directory (abc above). To permanently delete files on all computers, delete the file in 3 places: both computers and the USB Drive, otherwise it will continue to recreate itself in all places. You may also consider removing the /C option in the .bat files, which will erase any files missing when you synchronize - a dangerous option.

The first time you run this operation on the first computer and again on the second computer it will run slowly as it copies each file. Subsequent runs of the .bat files should be less intense and only copy changed files.