Have you ever needed to have multiple synchronized copies of the same folder or files on your PC? I'll admit, it's rare that I need this and most often it's easier to simply create shortcuts to files and folders. It's also easy to copy a folder or files and place it somewhere else, but how can you keep the all the copies updated if a file changes?
There are plenty of free sync tools out there that allow you to synchronize files and folders on a hard drive, but there is an easier way. I'm guessing that most of you have never heard of symbolic links (Unix/Linux) or hard links (Windows NT, 2000, XP, Vista).
Ever since Windows NT came out, you can create hard links to files and folders. These hard links make it look like you have multiple copies of files or folders when in fact they are only stored in one location. This saves file space and it means that you don't have to run file synchronizer software to keep all the copies updated. The only problem is that you can normally only create these links using command line tools. I don't like using the command window unless it's absolutely necessary.
I found a Windows shell extension called Hard Link Shell Extension that lets you right click on files and folders to create hard links. You can read more about it below.
Tip 1: Please note that this only works on a single hard drive. If you need to sync files between hard drives, see these free folder sync utilities. If you need to sync files between computers, I recommend DropBox, Windows Live Sync or similar services.
Tip 2: If you are using DropBox to synchronize files between computers over the internet, you may find that Hard Link Shell Extension is very handy. See LifeHacker's article: Sync Files and Folders Outside Your My Dropbox Folder
Quote from the website
Have you ever wanted to create hardlinks as it was possible with Unix, but not from the commandline but from the Explorer simply by right clicking an item? Take a look a the HardlinkShellExtension for WinNT/2K
Hardlinks provide the ability to keep a single copy of a file yet have it appear in multiple folders (directories). They can be created with the POSIX command ln included in the Windows Resource Kit or the fsutil command utility included in Windows XP. Thus, using standard Windows facilities Hardlinks can only be created at the command prompt, which can be tedious, especially when Hardlinks to multiple files are required or when one only makes occasional use of Hardlinks.